Optimization method and device for simulation semiconductor quantum dot device

Abstract

The invention relates to the technical field of quantum computers, in particular to an optimization method and device for a simulation semiconductor quantum dot device, and the method comprises the steps: fixing the voltage at a second quantum dot, and traversing the voltage at a first quantum dot in the simulation semiconductor quantum dot device within a preset voltage threshold, and obtaining a first energy level change curve graph; fixing the voltage at the first quantum dot, and traversing the voltage at the second quantum dot in the simulated semiconductor quantum dot device within a preset voltage threshold to obtain a second energy level change curve graph; and optimizing the simulated quantum dot device based on the energy level change curve graph. According to the method, the energy level change curve graphs of different quantum dots under different electrode voltages are determined in a QTCAD simulation system, so that the energy level regulation and control capability of the quantum dots is judged, and the energy level regulation and control capability of the quantum dots is indirectly adjusted by adjusting simulation parameters of a simulation semiconductor quantum dot device, so that the simulation semiconductor quantum dot device is optimized.

Description

Technical Field

[0001] The present invention relates to the field of quantum computer technology, and in particular to an optimization method and device for simulating semiconductor quantum dot devices. Background Art

[0002] The core idea of ​​semiconductor quantum computing is to use quantum dots in semiconductor quantum dot devices to realize quantum bits. Semiconductor quantum dot devices are made by making a series of electrodes on the surface of semiconductor heterojunctions or MOS (metal oxide semiconductor), and forming a deep enough potential well by regulating the electrode voltage, so that electrons are bound in the potential well. Since the potential well shape of semiconductor quantum dots is regulated by the electrode voltage, the reading of quantum bits can be realized by changing the electrode voltage. However, the realization of quantum computing requires the coupling of multiple quantum bits, and accordingly, more electrodes need to be added to the semiconductor surface to form more quantum dots. However, the semiconductor quantum dot devices actually produced have poor control ability of quantum dots, which will lead to low quality of semiconductor quantum dot devices and increase the difficulty of control in actual use. Therefore, it is necessary to simulate semiconductor quantum dot devices and optimize semiconductor quantum dot devices in the QTCAD (Quantum-Technology Computer-AidedDesign) simulation system. How to improve the control ability of each quantum dot in the simulation semiconductor quantum dot device in the QTCAD simulation system to optimize the simulation semiconductor quantum dot device is a technical problem that needs to be solved urgently. Summary of the invention

[0003] The present invention provides an optimization method and device for a simulated semiconductor quantum dot device, which are used to solve the problems of poor quantum dot control ability and low quality of the simulated semiconductor quantum dot device.

[0004] The embodiment of this specification provides an optimization method for a simulated semiconductor quantum dot device, wherein the simulated semiconductor quantum dot device includes quantum dots, and the quantum dots include at least a first quantum dot and a second quantum dot. The method includes:

[0005] Fixing the electrode voltage of the second quantum dot and traversing the electrode voltage of the first quantum dot within a preset voltage threshold;

[0006] Determine a first energy level change curve according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, energy values ​​corresponding to a plurality of wave functions obtained after traversing the electrode voltage of the first quantum dot, and coordinate expectation values ​​of the plurality of wave functions;

[0007] Fixing the electrode voltage of the first quantum dot and traversing the electrode voltage of the second quantum dot within the preset voltage threshold;

[0008] Determine a second energy level change curve according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the second quantum dot each time, and the coordinate expected values ​​of the multiple wave functions;

[0009] The simulated quantum dot device is optimized based on the first energy level change curve graph and the second energy level change curve graph.

[0010] Optionally, before fixing the voltage at the second quantum dot, the method further comprises:

[0011] Call the three-dimensional finite element mesh generator to draw the simulated semiconductor quantum dot device;

[0012] Simulation parameters are set for the simulated semiconductor quantum dot device.

[0013] Optionally, determining a first energy level change curve graph according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, energy values ​​corresponding to a plurality of wave functions obtained after traversing the electrode voltage of the first quantum dot, and coordinate expected values ​​of a plurality of wave functions includes:

[0014] Calculate first potential distribution data of the simulated semiconductor quantum dot device according to the electrode voltage of the second quantum dot, the electrode voltage of the traversed first quantum dot, the simulation parameters, and the Poisson equation;

[0015] Calculating a plurality of wave functions corresponding to the first potential distribution data and energy values ​​corresponding to the plurality of wave functions based on the potential distribution data and the Schrödinger equation;

[0016] Calculate the coordinate expectation values ​​of multiple wave functions according to the coordinate expectation value function;

[0017] Determining the center coordinates of the first quantum dot and the center coordinates of the second quantum dot;

[0018] Calculate the Euclidean distances of the expected values ​​of the coordinates of the plurality of wave functions to the center coordinates of the first quantum dot and the center coordinates of the second quantum dot respectively according to the Euclidean distance formula;

[0019] Determine the quantum dots to which the wave functions belong according to the Euclidean distance;

[0020] The first energy level change curve graph is determined based on the quantum dots to which the multiple wave functions belong and the energy values ​​corresponding to the multiple wave functions.

[0021] Optionally, determining the second energy level change curve according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the second quantum dot, and the coordinate expected values ​​of the multiple wave functions includes:

[0022] Calculate the second potential distribution data of the simulated semiconductor quantum dot device according to the electrode voltage of the first quantum dot, the electrode voltage of the traversed second quantum dot, the simulation parameters, and the Poisson equation;

[0023] Calculating a plurality of wave functions corresponding to the second potential distribution data and energy values ​​corresponding to the plurality of wave functions based on the potential distribution data and the Schrödinger equation;

[0024] Calculate the coordinate expectation values ​​of multiple wave functions according to the coordinate expectation value function;

[0025] Determining the center coordinates of the first quantum dot and the center coordinates of the second quantum dot;

[0026] Calculate the Euclidean distances of the expected values ​​of the coordinates of the plurality of wave functions to the center coordinates of the first quantum dot and the center coordinates of the second quantum dot respectively according to the Euclidean distance formula;

[0027] Determine the quantum dots to which the wave functions belong according to the Euclidean distance;

[0028] The second energy level change curve is determined based on the quantum dots to which the multiple wave functions belong and the energy values ​​corresponding to the multiple wave functions.

[0029] Optionally, determining the quantum dots to which the wave functions belong according to the Euclidean distance includes:

[0030] When the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the first quantum dot is smaller than the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the second quantum dot, the wave function belongs to the first quantum dot;

[0031] When the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the second quantum dot is smaller than the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the first quantum dot, the wave function belongs to the second quantum dot.

[0032] Optionally, the optimizing the simulated semiconductor quantum dot device based on the first energy level change curve graph and the second energy level change curve graph includes:

[0033] Performing curve fitting on the first energy level change curve graph to obtain a first curve slope set, wherein the first curve slope set includes a first curve slope group of the first quantum dot and a second curve slope group of the second quantum dot when the voltage at the first target quantum dot is changed;

[0034] Performing curve fitting on the second energy level change curve graph to obtain a second curve slope set, wherein the second curve slope set includes a third curve slope group of the first quantum dot and a fourth curve slope group of the second quantum dot when the voltage at the second target quantum dot is changed;

[0035] When the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group do not meet the preset curve slope, adjusting the simulation parameters until the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group meet the preset curve slope;

[0036] The simulated semiconductor quantum dot device corresponding to the simulation parameters satisfying the preset curve slope is determined to be an optimized simulated quantum dot device.

[0037] Optionally, performing curve fitting on the first energy level change curve graph includes:

[0038] Using the least square method to perform curve fitting on each curve in the first energy level change curve diagram;

[0039] The performing curve fitting on the second energy level change curve graph comprises:

[0040] The least square method is used to perform curve fitting on each curve in the second energy level change curve diagram.

[0041] The embodiment of this specification also provides an optimization device for simulating a semiconductor quantum dot device, including:

[0042] A first voltage traversal module, used to fix the electrode voltage of the second quantum dot and traverse the electrode voltage of the first quantum dot within a preset voltage threshold;

[0043] A first energy level change curve diagram determination module, used to determine the first energy level change curve diagram according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the first quantum dot, and the coordinate expected values ​​of the multiple wave functions;

[0044] A second voltage traversal module, used to fix the electrode voltage of the first quantum dot and traverse the electrode voltage of the second quantum dot within the preset voltage threshold;

[0045] A second energy level change curve diagram determination module, used to determine the second energy level change curve diagram according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the second quantum dot each time, and the coordinate expected values ​​of the multiple wave functions;

[0046] A device optimization module is used to optimize the simulated quantum dot device based on the first energy level change curve graph and the second energy level change curve graph.

[0047] An electronic device comprises a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute the method described above.

[0048] A storage medium, characterized in that a computer program is stored in the storage medium, and the computer program is configured to execute the above-mentioned method when running.

[0049] Its beneficial effects are as follows: the present invention fixes the voltage at the second quantum dot, and sequentially traverses the voltage at the first quantum dot in the simulated semiconductor quantum dot device within a preset voltage threshold to obtain a first energy level change curve graph; fixes the voltage at the first quantum dot, and sequentially traverses the voltage at the second quantum dot in the simulated semiconductor quantum dot device within a preset voltage threshold to obtain a second energy level change curve graph; then, the simulated quantum dot device is optimized based on the energy level change curve graph, and the energy level control capability of the quantum dot is determined by determining the energy level change curve graph of different quantum dots under different electrode voltages in the QTCAD simulation system, thereby indirectly adjusting the quantum dot energy level control capability by adjusting the simulation parameters of the simulated semiconductor quantum dot device to optimize the simulated semiconductor quantum dot device. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0051] Figure 1 The schematic diagram of quantum dot energy levels provided in this specification;

[0052] Figure 2 A schematic diagram of the energy levels of double quantum dots provided for this specification;

[0053] Figure 3 A schematic diagram of the principle of an optimization method for simulating semiconductor quantum dot devices provided in an embodiment of this specification;

[0054] Figure 4 Schematic diagram of the expected value of the one-dimensional wave function coordinates and the center coordinates of the double quantum dots provided in this manual

[0055] Figure 5 The energy level change curve diagram of the energy levels corresponding to different quantum states in the double quantum dots provided in this specification as the electrode voltage V1 changes;

[0056] Figure 6 A schematic diagram of the structure of an optimization device for simulating semiconductor quantum dot devices provided in an embodiment of this specification;

[0057] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of this specification;

[0058] Figure 8 A schematic diagram of a computer-readable medium provided for an embodiment of this specification. DETAILED DESCRIPTION

[0059] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, but should not be construed as limiting the present invention.

[0060] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, but should not be construed as limiting the present invention.

[0061] It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0062] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0063] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0064] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0065] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0066] For a single quantum dot, Figure 1 As shown in , all quantum states belong to the same quantum dot, and different quantum states can be distinguished from low to high energy. However, for multiple quantum dots, taking double quantum dots as an example, Figure 2As shown in the figure, when the electrode voltage at quantum dot 1 is changed, the energy level of quantum dot 1 changes faster, while the energy level of quantum dot 2 changes slower. On the contrary, when the electrode voltage at quantum dot 2 is changed, the energy level of quantum dot 2 changes faster, while the energy level of quantum dot 1 changes slower. When the two electrode voltages are changed at the same time, the energy levels of different quantum dots may be reversed, that is, energy level inversion occurs. At this time, if all energy levels are still sorted by energy level, the position of energy levels will suddenly change, where Figure 1 , Figure 1 The S in represents the source, and D represents the drain. The top of the source S and the drain D represent the chemical potential.

[0067] When energy level reversal occurs, if we continue to arrange the energy levels in order from small to large, we will not be able to correctly fit the slope of the energy level curve, and thus cannot describe the regulation of different quantum by the electrode. However, we found that the slope of the energy level curve at the same quantum dot is almost the same, and no energy level crossing occurs during the voltage change. Therefore, before fitting the slope of the energy level curve, we need to distinguish different energy levels according to the quantum dots they belong to. How to distinguish different energy levels according to the quantum dots they belong to in order to achieve the slope fitting of the energy level curve is a technical problem we need to solve, so as to achieve the optimization and simulation of semiconductor quantum dot devices based on the slope of the fitted energy level curve. Now, an optimization method and device for simulating semiconductor quantum dot devices are provided.

[0068] Reference Figure 3 A schematic diagram of a principle of an optimization method for a simulated semiconductor quantum dot device provided in an embodiment of this specification, wherein the simulated semiconductor quantum dot device includes quantum dots, wherein the quantum dots include at least a first quantum dot and a second quantum dot, and the method includes:

[0069] S101: fixing the electrode voltage of the second quantum dot and traversing the electrode voltage of the first quantum dot within a preset voltage threshold;

[0070] Optionally, before fixing the voltage at the second quantum dot, the method further comprises:

[0071] Call the three-dimensional finite element mesh generator to draw the simulated semiconductor quantum dot device;

[0072] Simulation parameters are set for the simulated semiconductor quantum dot device.

[0073] In an optional embodiment, it is necessary to first call a three-dimensional finite element mesh generator to draw a simulated semiconductor quantum dot device, and then set simulation parameters for the simulated semiconductor quantum dot device, including electrode size, thickness of each layer of material in the simulated semiconductor quantum dot device, material of each layer of material, etc.; then, fix the voltage at the second quantum dot, and when traversing the voltage at the first quantum dot in the simulated semiconductor quantum dot device within a preset voltage threshold, the initial voltage at the first quantum dot can be set to V1 and the voltage at the second quantum dot can be set to V2. The online simulation of semiconductor quantum dot devices is realized by the above-mentioned simulation method, avoiding the cost loss caused by offline production. Subsequently, production can be carried out based on the optimized simulated semiconductor quantum dot device, improving the quality of semiconductor quantum dot devices in actual production, saving costs, and better meeting actual needs.

[0074] S102: Determine a first energy level change curve according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, energy values ​​corresponding to multiple wave functions obtained after traversing the electrode voltage of the first quantum dot, and expected values ​​of coordinates of multiple wave functions.

[0075] Optionally, determining the first energy level change curve graph according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the plurality of wave functions obtained after traversing the electrode voltage of the first quantum dot, and the coordinate expected values ​​of the plurality of wave functions includes:

[0076] Calculate first potential distribution data of the simulated semiconductor quantum dot device according to the electrode voltage of the second quantum dot, the electrode voltage of the traversed first quantum dot, the simulation parameters, and the Poisson equation;

[0077] Calculating a plurality of wave functions corresponding to the first potential distribution data and energy values ​​corresponding to the plurality of wave functions based on the potential distribution data and the Schrödinger equation;

[0078] Calculate the coordinate expectation values ​​of multiple wave functions according to the coordinate expectation value function;

[0079] Determining the center coordinates of the first quantum dot and the center coordinates of the second quantum dot;

[0080] Calculate the Euclidean distances of the expected values ​​of the coordinates of the plurality of wave functions to the center coordinates of the first quantum dot and the center coordinates of the second quantum dot respectively according to the Euclidean distance formula;

[0081] Determine the quantum dots to which the wave functions belong according to the Euclidean distance;

[0082] The first energy level change curve graph is determined based on the quantum dots to which the multiple wave functions belong and the energy values ​​corresponding to the multiple wave functions.

[0083] The step of determining the quantum dots to which the wave functions belong based on the Euclidean distance comprises:

[0084] When the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the first quantum dot is smaller than the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the second quantum dot, the wave function belongs to the first quantum dot;

[0085] When the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the second quantum dot is smaller than the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the first quantum dot, the wave function belongs to the second quantum dot.

[0086] In an optional embodiment, taking the voltage at the first quantum dot as V1 and the voltage at the second quantum dot as V2 as an example, the potential distribution data of the simulated semiconductor quantum dot device is calculated according to the simulation parameters, the voltage V1 at the first quantum dot, the voltage V2 at the second quantum dot, and the Poisson equation, and the Schrödinger equation is calculated according to the potential distribution data to obtain multiple wave functions corresponding to the potential distribution data. The energy values ​​corresponding to multiple wave functions [E1, E2, ..., E n ], each traversal action will obtain a set of the above-mentioned wave functions and the energy values ​​corresponding to the wave functions, wherein i is the i-th wave function, n is the n-th energy, i=n, ​​i and n are positive integers greater than zero, the wave function is the wave function in three-dimensional space, and the electrode voltage of the first quantum dot is the pump electrode voltage corresponding to the first quantum dot.

[0087] The wave function in three-dimensional space For example, the coordinate expected value function is as follows:

[0088]

[0089]

[0090]

[0091] in, is the wave function The expected value of the coordinate on the x-axis, is the wave function The expected value of the coordinate on the y-axis, is the wave function The expected value of the coordinate on the z-axis, that is, the wave function The expected coordinate value is for The conjugate function of .

[0092] Before calculating the Euclidean distance, it is necessary to measure the center coordinates of the two quantum dots. Let the center coordinates of quantum dot 1 be (X1, Y1, Z1) and the center coordinates of quantum dot 2 be (X2, Y2, Z2). Then use the Euclidean distance calculation formula to calculate the center coordinates of quantum dot 1 to the wave function. The expected value of the coordinates Distance Center coordinates of quantum dot 2 to wave function The expected value of the coordinates Distance The calculation formula is as follows:

[0093]

[0094]

[0095] when hour, Belongs to quantum dot 1, when hour, Belongs to quantum dot 2. The above method is used to distinguish the quantum dots to which the wave function belongs, thereby distinguishing the quantum dots to which the wave function belongs at different energy levels, providing data support for the slope fitting of the subsequent energy level curve.

[0096] Since the quantum dots to which the wave functions belong are distinguished by the above method, the energy values ​​corresponding to the wave functions can be divided into corresponding quantum dots according to the conditions of the quantum dots to which the wave functions belong, and the energy level [E a1 ,E a2 ,...,E ak ] and the energy level [E b1 ,E b2 ,...,E b，l ], where a and b are the identifiers of the quantum dots to which the energy belongs, k represents the kth energy, l represents the lth energy, and k+l=n. Then, according to the energy level [E a1 ,E a2 ,...,E ak ] and the energy level [E b1 ,E b2 ,...,E b，l ] and a preset voltage threshold to construct a first energy level change curve diagram. As shown in 5, it is an energy level change curve diagram in which the energy levels corresponding to different quantum states in the double quantum dots change with the electrode voltage V1. The horizontal axis of the energy level change curve diagram is the preset voltage threshold, and the vertical axis is energy.

[0097] If the above process of the present invention is not used to distinguish the quantum dots with different energy levels of wave functions, then Figure 5It can be seen that curve 9 and curve 10 form an energy level inversion, and curve 9 is connected by the first half of curve 9, curve 090, and the second half of curve 9, curve 091. Since the slopes of the energy level curves at the same quantum dot are almost the same, the slope of curve 9 cannot represent the quantum state of the corresponding quantum dot. The method described in the present invention can identify which wave function energies belong to the corresponding quantum dot, thereby obtaining the slopes of the real energy level curves corresponding to different quantum dots, that is, the first half of curve 9, curve 090, and the second half of curve 10, curve 10, constitute the slope of the energy level curve of quantum dot 2 at the corresponding energy level, the second half of curve 9, curve 091, and the first half of curve 10, curve 10, constitute the slope of the energy level curve of quantum dot 1 at the corresponding energy level, and curves 5 and 6 can be used to determine the energy level of quantum dot 2. Line 6, curve 7, and curve 8 also have energy level inversion. The method for judging the slope of the energy level curve is the same as that of curve 9 and curve 10, which will not be repeated here. Finally, the curve composed of curve 1, curve 3, the first half of curve 6 and the second half of curve 5, the curve composed of the first half of curve 8 and the second half of curve 7, the curve composed of the first half of curve 10 0100 and the second half of curve 9 091 belongs to the energy level change curve corresponding to quantum dot 1, and the curve composed of curve 2, curve 4, the first half of curve 5 and the second half of curve 6, the curve composed of the first half of curve 7 and the second half of curve 8, the curve composed of the first half of curve 9 090 and the second half of curve 10 0101 belongs to the energy level change curve corresponding to quantum dot 1.

[0098] In an optional embodiment, for ease of understanding, the wave function in one dimension is For example, Figure 4 As shown, The expected value of the coordinate on the x-axis is X1 is the center coordinate of quantum dot 1, and X2 is the center coordinate of quantum dot 2. It can be seen from the figure that the center coordinate X1 of quantum dot 1 to the wave function The expected value of the coordinate on the x-axis The Euclidean distance d1 is smaller than the center coordinate x1 of quantum dot 2 to the wave function The expected value of the coordinate on the x-axis The Euclidean distance d2, therefore, the wave function belongs to quantum dot 1, so the wave function The corresponding energy level belongs to quantum dot 1.

[0099] S103: fixing the electrode voltage of the first quantum dot, and traversing the electrode voltage of the second quantum dot within the preset voltage threshold;

[0100] S104: determining a second energy level change curve according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, energy values ​​corresponding to a plurality of wave functions obtained after traversing the electrode voltage of the second quantum dot each time, and coordinate expected values ​​of the plurality of wave functions;

[0101] Optionally, determining the second energy level change curve according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the second quantum dot each time, and the coordinate expected values ​​of the multiple wave functions includes:

[0102] Calculate the second potential distribution data of the simulated semiconductor quantum dot device according to the electrode voltage of the first quantum dot, the electrode voltage of the traversed second quantum dot, the simulation parameters, and the Poisson equation;

[0103] Calculating a plurality of wave functions corresponding to the second potential distribution data and energy values ​​corresponding to the plurality of wave functions based on the potential distribution data and the Schrödinger equation;

[0104] Calculate the coordinate expectation values ​​of multiple wave functions according to the coordinate expectation value function;

[0105] Determining the center coordinates of the first quantum dot and the center coordinates of the second quantum dot;

[0106] Calculate the Euclidean distances of the expected values ​​of the coordinates of the plurality of wave functions to the center coordinates of the first quantum dot and the center coordinates of the second quantum dot respectively according to the Euclidean distance formula;

[0107] Determine the quantum dots to which the wave functions belong according to the Euclidean distance;

[0108] The second energy level change curve is determined based on the quantum dots to which the multiple wave functions belong and the energy values ​​corresponding to the multiple wave functions.

[0109] In an optional embodiment, the process of determining the second energy level change curve graph is basically the same as the process of determining the first energy level change curve graph. The difference is that the voltage at the first quantum dot is fixed, and the voltage at the second quantum dot is changed. The specific process can refer to the process of obtaining the first energy level change curve graph, which will not be repeated here. The voltage at the second quantum dot is the pump electrode voltage corresponding to the second quantum dot.

[0110] S105: Optimizing the simulated quantum dot device based on the first energy level change curve graph and the second energy level change curve graph.

[0111] In an optional embodiment, the least squares method is used to perform curve fitting on each curve in the first energy level change curve diagram and each curve in the second energy level change curve diagram to obtain a first curve slope set and a second curve slope set, wherein the first curve slope set includes a first curve slope group of the first quantum dot and a second curve slope group of the second quantum dot when the voltage at the first target quantum dot is changed; the second curve slope set includes a third curve slope group of the first quantum dot and a fourth curve slope group of the second quantum dot when the voltage at the second target quantum dot is changed; when the first curve slope group and the second When the curve slope group, the third curve slope group, and the fourth curve slope group do not meet the simulation requirements, the simulation parameters are adjusted to change the structure of the simulated semiconductor quantum dot device, thereby causing the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group to change, and the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group are determined in real time. When the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group meet the preset curve slope, the simulated semiconductor quantum dot device corresponding to the simulation parameters that meet the preset curve slope is an optimized simulated quantum dot device. Among them, the preset curve slope is the curve slope difference threshold and the curve slope threshold, and the preset curve slope can also be modified according to the actual needs of quantum bit reading.

[0112] In an optional embodiment, when a semiconductor quantum dot device is actually used, it is found that the smaller the difference in the slope of the curve and the larger the slope value, the higher the efficiency of reading the quantum bit. Therefore, during simulation, the various simulation parameters of the simulated semiconductor quantum dot device with a smaller difference in the slope of the curve and a larger slope value can be selected as the parameters for the actual production of semiconductor quantum dot devices for production.

[0113] In an optional embodiment, the method of the present invention is applicable not only to two quantum dots, but also to multiple quantum dots, and there is no limitation on the number of quantum dots.

[0114] The present invention fixes the voltage at the second quantum dot, and sequentially traverses the voltage at the first quantum dot in the simulated semiconductor quantum dot device within a preset voltage threshold to obtain a first energy level change curve graph; fixes the voltage at the first quantum dot, and sequentially traverses the voltage at the second quantum dot in the simulated semiconductor quantum dot device within a preset voltage threshold to obtain a second energy level change curve graph; then, the simulated quantum dot device is optimized based on the energy level change curve graph, and the energy level control capability of the quantum dot is determined by determining the energy level change curve graph under different electrode voltages of different quantum dots in the QTCAD simulation system, thereby indirectly adjusting the quantum dot energy level control capability by adjusting the simulation parameters of the simulated semiconductor quantum dot device to optimize the simulated semiconductor quantum dot device.

[0115] Reference Figure 6 A schematic diagram of a structure of an optimization device for simulating semiconductor quantum dot devices provided in an embodiment of this specification includes:

[0116] A first voltage traversal module 201, used to fix the electrode voltage of the second quantum dot and traverse the electrode voltage of the first quantum dot within a preset voltage threshold;

[0117] A first energy level change curve diagram determination module 202, configured to determine a first energy level change curve diagram according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, energy values ​​corresponding to a plurality of wave functions obtained after traversing the electrode voltage of the first quantum dot, and coordinate expected values ​​of a plurality of wave functions;

[0118] A second voltage traversal module 203, used to fix the electrode voltage of the first quantum dot and traverse the electrode voltage of the second quantum dot within the preset voltage threshold;

[0119] A second energy level change curve diagram determination module 204 is used to determine a second energy level change curve diagram according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the second quantum dot each time, and the coordinate expected values ​​of the multiple wave functions;

[0120] The device optimization module 205 is used to optimize the simulated quantum dot device based on the first energy level change curve graph and the second energy level change curve graph.

[0121] Optionally, the device further comprises:

[0122] The device simulation module is used to call the three-dimensional finite element mesh generator to draw and simulate semiconductor quantum dot devices;

[0123] A parameter setting module is used to set simulation parameters for the simulated semiconductor quantum dot device.

[0124] Optionally, the first energy level change curve diagram determining module 202 includes:

[0125] A first potential distribution data calculation unit, configured to calculate first potential distribution data of the simulated semiconductor quantum dot device according to the electrode voltage of the second quantum dot, the electrode voltage of the traversed first quantum dot, the simulation parameters, and the Poisson equation;

[0126] A first wave function calculation unit, configured to calculate a plurality of wave functions corresponding to the first potential distribution data and energy values ​​corresponding to the plurality of wave functions based on the potential distribution data and the Schrödinger equation;

[0127] A first coordinate expectation value calculation unit, used for calculating the coordinate expectation values ​​of multiple wave functions according to the coordinate expectation value function;

[0128] A first center coordinate determining unit, used to determine the center coordinates of the first quantum dot and the center coordinates of the second quantum dot;

[0129] A first Euclidean distance calculation unit, used to calculate the Euclidean distances of the coordinate expectation values ​​of the plurality of wave functions to the center coordinates of the first quantum dot and the Euclidean distances of the center coordinates of the second quantum dot according to the Euclidean distance formula;

[0130] A first quantum dot attribution determination unit, configured to determine the quantum dots to which the wave functions belong according to the Euclidean distance;

[0131] The first energy level change curve diagram determining unit is used to determine the first energy level change curve diagram based on the quantum dots to which the wave functions belong and the energy values ​​corresponding to the wave functions.

[0132] Optionally, the second energy level change curve diagram determining module 204 includes:

[0133] A second potential distribution data calculation unit, configured to calculate second potential distribution data of the simulated semiconductor quantum dot device according to the electrode voltage of the first quantum dot, the electrode voltage of the traversed second quantum dot, the simulation parameters, and the Poisson equation;

[0134] A second wave function calculation unit, used for calculating a plurality of wave functions corresponding to the second potential distribution data and energy values ​​corresponding to the plurality of wave functions based on the potential distribution data and the Schrödinger equation;

[0135] A second coordinate expectation value calculation unit, used to calculate the coordinate expectation values ​​of multiple wave functions according to the coordinate expectation value function;

[0136] A second center coordinate determining unit, to determine the center coordinates of the first quantum dot and the center coordinates of the second quantum dot;

[0137] A second Euclidean distance calculation unit calculates the Euclidean distances of the expected values ​​of the coordinates of the plurality of wave functions to the center coordinates of the first quantum dot and the center coordinates of the second quantum dot according to the Euclidean distance formula;

[0138] A second quantum dot attribution determination unit, configured to determine the quantum dots to which the wave functions belong based on the Euclidean distance;

[0139] The second energy level change curve diagram determining unit is used to determine the second energy level change curve diagram based on the quantum dots to which the wave functions belong and the energy values ​​corresponding to the wave functions.

[0140] Optionally, the first quantum dot attribution determination unit and the second quantum dot attribution determination unit both include:

[0141] A first quantum dot determination subunit, configured to determine that the wave function belongs to the first quantum dot when the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the first quantum dot is smaller than the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the second quantum dot;

[0142] The second quantum dot determination subunit is used to determine that the wave function belongs to the second quantum dot when the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the second quantum dot is smaller than the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the first quantum dot.

[0143] Optionally, the device optimization module 205 includes:

[0144] A first curve fitting unit is used to perform curve fitting on the first energy level change curve diagram to obtain a first curve slope set, wherein the first curve slope set includes a first curve slope group of the first quantum dot and a second curve slope group of the second quantum dot when the voltage at the first target quantum dot is changed;

[0145] A second curve fitting unit is used to perform curve fitting on the second energy level change curve graph to obtain a second curve slope set, wherein the second curve slope set includes a third curve slope group of the first quantum dot and a fourth curve slope group of the second quantum dot when the voltage at the second target quantum dot is changed;

[0146] A simulation quantum dot device optimization unit, used for adjusting the simulation parameters when the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group do not meet the simulation requirements, until the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group meet the simulation requirements;

[0147] The simulated quantum dot device determination unit is used to determine that the simulated semiconductor quantum dot device corresponding to the simulation parameters that meet the simulation requirements is an optimized simulated quantum dot device.

[0148] Optionally, the first curve fitting unit includes:

[0149] A first curve fitting subunit, used for performing curve fitting on each curve in the first energy level change curve diagram by using a least square method;

[0150] The second curve fitting unit comprises:

[0151] The second curve fitting subunit is used to perform curve fitting on each curve in the second energy level change curve diagram by using the least square method.

[0152] Regarding the device in the above embodiment, the process of executing the operation in each step has been described in detail in the embodiment of the method, and will not be elaborated here.

[0153] Based on the same inventive concept, an embodiment of this specification also provides an electronic device.

[0154] The following describes an electronic device embodiment of the present invention, which can be regarded as a specific physical implementation of the method and device embodiments of the present invention. The details described in the electronic device embodiment of the present invention should be regarded as a supplement to the above method or device embodiments; details not disclosed in the electronic device embodiment of the present invention can be implemented with reference to the above method or device embodiments.

[0155] Reference Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this specification. Figure 7 The electronic device 300 according to the embodiment of the present invention is described. Figure 7 The electronic device 300 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0156] like Figure 7 As shown, the electronic device 300 is in the form of a general computing device. The components of the electronic device 300 may include, but are not limited to: at least one processing unit 310, at least one storage unit 320, a bus 330 connecting different device components (including the storage unit 320 and the processing unit 310), a display unit 340, etc.

[0157] The storage unit stores program codes, which can be executed by the processing unit 310, so that the processing unit 310 performs the steps according to various exemplary embodiments of the present invention described in the above processing method section of this specification. For example, the processing unit 310 can perform the following steps: Figure 3 Steps shown.

[0158] The storage unit 320 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 3201 and / or a cache memory unit 3202 , and may further include a read-only memory unit (ROM) 3203 .

[0159] The storage unit 320 may also include a program / utility 3204 having a set (at least one) of program modules 3205, such program modules 3205 including but not limited to: operating means, one or more application programs, other program modules and program data, each of which or some combination may include the implementation of a network environment.

[0160] Bus 330 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0161] The electronic device 300 may also communicate with one or more external devices 400 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable a user to interact with the electronic device 300, and / or any device that enables the electronic device 300 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed through an input / output (I / O) interface 350. Furthermore, the electronic device 300 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 360. The network adapter 360 may communicate with other modules of the electronic device 300 through the bus 330. It should be understood that although Figure 7 Not shown, other hardware and / or software modules may be used in conjunction with the electronic device 300, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID devices, tape drives, and data backup storage devices.

[0162] Through the description of the above implementation methods, it is easy for those skilled in the art to understand that the exemplary embodiments described in the present invention can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the implementation method of the present invention can be embodied in the form of a software product, which can be stored in a computer-readable storage medium (which can be a CD-ROM, USB flash drive, mobile hard disk, etc.) or on a network, including a number of instructions to enable a computing device (which can be a personal computer, server, or network device, etc.) to execute the above method according to the present invention. When the computer program is executed by a data processing device, the computer-readable medium can implement the above method of the present invention, that is: Figure 3 The method shown.

[0163] Reference Figure 8 A schematic diagram of a computer-readable medium provided for an embodiment of this specification.

[0164] accomplish Figure 3 The computer program of the method shown can be stored on one or more computer readable media. The computer readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor device, device or component, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0165] The computer readable storage medium may include a data signal propagated in a baseband or as part of a carrier wave, wherein a readable program code is carried. This propagated data signal may take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. The readable storage medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution device, device, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above.

[0166] Program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0167] In summary, the present invention can be implemented in hardware, or in a software module running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that general data processing devices such as microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components in the embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0168] The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the present invention is not inherently related to any specific computer, virtual device or electronic device, and various general devices can also implement the present invention. The above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0169] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0170] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An optimization method for simulating semiconductor quantum dot devices, characterized in that: The simulated semiconductor quantum dot device includes quantum dots, and the quantum dots include at least a first quantum dot and a second quantum dot. The method includes: Fixing the electrode voltage of the second quantum dot and traversing the electrode voltage of the first quantum dot within a preset voltage threshold; Determine a first energy level change curve according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, energy values ​​corresponding to a plurality of wave functions obtained after traversing the electrode voltage of the first quantum dot, and coordinate expected values ​​of the plurality of wave functions; Fixing the electrode voltage of the first quantum dot and traversing the electrode voltage of the second quantum dot within the preset voltage threshold; Determine a second energy level change curve according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the second quantum dot each time, and the coordinate expected values ​​of the multiple wave functions; The simulated quantum dot device is optimized based on the first energy level change curve graph and the second energy level change curve graph.

2. The method according to claim 1, characterized in that Before fixing the voltage at the second quantum dot, the method comprises: Call the three-dimensional finite element mesh generator to draw the simulated semiconductor quantum dot device; Simulation parameters are set for the simulated semiconductor quantum dot device.

3. The method according to claim 2, characterized in that Determining a first energy level change curve diagram according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the plurality of wave functions obtained after traversing the electrode voltage of the first quantum dot, and the coordinate expectation values ​​of the plurality of wave functions, including: Calculate first potential distribution data of the simulated semiconductor quantum dot device according to the electrode voltage of the second quantum dot, the electrode voltage of the traversed first quantum dot, the simulation parameters, and the Poisson equation; Calculating a plurality of wave functions corresponding to the first potential distribution data and energy values ​​corresponding to the plurality of wave functions based on the potential distribution data and the Schrödinger equation; Calculate the coordinate expectation values ​​of multiple wave functions according to the coordinate expectation value function; Determining the center coordinates of the first quantum dot and the center coordinates of the second quantum dot; Calculate the Euclidean distances of the expected values ​​of the coordinates of the plurality of wave functions to the center coordinates of the first quantum dot and the center coordinates of the second quantum dot respectively according to the Euclidean distance formula; Determine the quantum dots to which the wave functions belong according to the Euclidean distance; The first energy level change curve graph is determined based on the quantum dots to which the multiple wave functions belong and the energy values ​​corresponding to the multiple wave functions.

4. The method according to claim 2, characterized in that The second energy level change curve diagram is determined according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the second quantum dot, and the coordinate expected values ​​of the multiple wave functions, including: Calculate the second potential distribution data of the simulated semiconductor quantum dot device according to the electrode voltage of the first quantum dot, the electrode voltage of the traversed second quantum dot, the simulation parameters, and the Poisson equation; Calculating a plurality of wave functions corresponding to the second potential distribution data and energy values ​​corresponding to the plurality of wave functions based on the potential distribution data and the Schrödinger equation; Calculate the coordinate expectation values ​​of multiple wave functions according to the coordinate expectation value function; Determining the center coordinates of the first quantum dot and the center coordinates of the second quantum dot; Calculate the Euclidean distances of the expected values ​​of the coordinates of the plurality of wave functions to the center coordinates of the first quantum dot and the center coordinates of the second quantum dot respectively according to the Euclidean distance formula; Determine the quantum dots to which the wave functions belong according to the Euclidean distance; The second energy level change curve is determined based on the quantum dots to which the multiple wave functions belong and the energy values ​​corresponding to the multiple wave functions.

5. The method according to claim 3 or 4, characterized in that The step of determining the quantum dots to which the wave functions belong based on the Euclidean distance comprises: When the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the first quantum dot is smaller than the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the second quantum dot, the wave function belongs to the first quantum dot; When the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the second quantum dot is smaller than the Euclidean distance from the expected value of the coordinates of the wave function to the center coordinates of the first quantum dot, the wave function belongs to the second quantum dot.

6. The method according to claim 1, characterized in that The optimizing the simulated semiconductor quantum dot device based on the first energy level change curve graph and the second energy level change curve graph includes: Performing curve fitting on the first energy level change curve graph to obtain a first curve slope set, wherein the first curve slope set includes a first curve slope group of the first quantum dot and a second curve slope group of the second quantum dot when the voltage at the first target quantum dot is changed; Performing curve fitting on the second energy level change curve graph to obtain a second curve slope set, wherein the second curve slope set includes a third curve slope group of the first quantum dot and a fourth curve slope group of the second quantum dot when the voltage at the second target quantum dot is changed; When the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group do not meet the preset curve slope, adjusting the simulation parameters until the first curve slope group, the second curve slope group, the third curve slope group, and the fourth curve slope group meet the preset curve slope; The simulated semiconductor quantum dot device corresponding to the simulation parameters satisfying the preset curve slope is determined to be an optimized simulated quantum dot device.

7. The method according to claim 6, characterized in that The performing curve fitting on the first energy level change curve graph comprises: Using the least square method to perform curve fitting on each curve in the first energy level change curve diagram; The performing curve fitting on the second energy level change curve graph comprises: The least square method is used to perform curve fitting on each curve in the second energy level change curve diagram.

8. An optimization device for simulating semiconductor quantum dot devices, which is implemented based on the method described in any one of claims 1 to 7, characterized in that ,include: A first voltage traversal module, used to fix the electrode voltage of the second quantum dot and traverse the electrode voltage of the first quantum dot within a preset voltage threshold; A first energy level change curve diagram determination module, used to determine the first energy level change curve diagram according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the first quantum dot, and the coordinate expected values ​​of the multiple wave functions; A second voltage traversal module, used to fix the electrode voltage of the first quantum dot and traverse the electrode voltage of the second quantum dot within the preset voltage threshold; A second energy level change curve diagram determination module, used to determine the second energy level change curve diagram according to the center coordinates of the first quantum dot, the center coordinates of the second quantum dot, the energy values ​​corresponding to the multiple wave functions obtained after traversing the electrode voltage of the second quantum dot each time, and the coordinate expected values ​​of the multiple wave functions; A device optimization module is used to optimize the simulated quantum dot device based on the first energy level change curve graph and the second energy level change curve graph.

9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute the method according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores a computer program, and the computer program is configured to execute the method according to any one of claims 1 to 7 when running.

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