Interference experimental device for verifying relative uncertainty in quantum state

Abstract

To provide an interference experimental device for detecting and verifying relative uncertainty due to an observation system in a quantum state by interference.SOLUTION: The constitution of emitting a pulse A from first light pulse generation means and a pulse B from second light pulse generation means, controlling the optical state of the pulse A by the output result of quantum random number generation means and detecting interference between the probability wave of the pulse A and the pulse B by PD and OSA can verify whether a quantum probable result decided in the observation system of an experimenter is undecided or not in the observation system of the pulse B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an interference experimental device for interferometrically verifying the relative uncertainty of an observation system of a quantum state, and in particular to a device that performs external interferometric observation of a classical state that has been determined by probabilistic branching, making it possible to verify whether the state has the stochastic wave properties of quantum superposition through the presence or absence of interference, and that obtains probabilistic results that would not have existed in the observation system of the experimenter in charge of the device. [Background technology]

[0002] In conventional quantum delayed choice experiments (so-called Wheeler-type experiments), single photons or entangled photon pairs are used, and whether or not the same photon undergoes self-interference via a double slit or similar is determined by the observer's subsequent choice. This has led to reports of a phenomenon in which the "path" of a photon is determined a posteriori by observation.

[0003] However, in these experiments, the photons themselves, which are involved in interference, are both the object of observation and the subject of the observation. Therefore, the relationship between the collapse of the wave function due to observation and the coherence destruction is inevitably intertwined, making it difficult to independently question the possibility that the determination of the quantum state may occur depending on the observer's frame of reference, i.e., the "relative uncertainty" due to the observation system. The technical challenge is to realize an interference experiment device using an independent light source to verify the "relative uncertainty."

[0004] Furthermore, in recent quantum interference experiments in general, many configurations have been proposed, mainly using single photons or entanglement. However, quantum interference and selective control of coherent pulses consisting of multiple photons remains largely unexplored in both theory and experiment, and experimental methods for verifying this are limited. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention is an interference experimental device for interferometrically verifying the relative uncertainty due to the observation system of a quantum state, and aims to provide an experimental device for interferometrically verifying the possibility that contraction due to quantum observation occurs relatively depending on the observation system, using a separate observation system that is quantum independent from the experimenter's observation system.

[0006] Unlike conventional Wheeler-type experiments, in the present invention, 1. Using two independent coherent optical pulses (pulse A and pulse B), 2. Pulse A is an object that maintains a quantum state, and pulse B plays the role of an observer that observes it by interfering with the probability wave of pulse A. 3. Pulse B interferes with Pulse A before receiving information from the environment that determines the state of Pulse A (e.g., the output of the QRNG), 4. The existence of "uncertainty" in the reference frame of the observation system will be verified through the presence or absence of the interference results (especially the beats resulting from the interference).

[0007] This structure makes it possible to verify whether the QRNG output result and the accompanying optical state of pulse A, which are considered to have been observed, i.e., determined, from the experimenter's observation system, which is the environmental system in which the experimental equipment is placed, are indeterminate from the perspective of pulse B, which can be interpreted as being independent of the environmental system because it has not been observed from the environmental system, by checking whether interference phenomena occur, and is expected to provide new insights into the observation problems of quantum mechanics. [Means for solving the problem]

[0008] Unlike the prior art, the present invention is an interference experimental device for interferometrically verifying the relative uncertainty of quantum states, and comprises the following components:

[0009] (1) QRNG (Quantum Random Number Generator): It is a means for generating a probabilistically determined output (e.g., 0 or 1), which is used to control the optical state of pulse A. Note that the output of the QRNG may be in a form that is not limited to binary. (2) First optical pulse generating means: This is a means of emitting pulse A from an independent light source, and this pulse is optically controlled according to the output result of the subsequent QRNG, thereby maintaining its quantum state and becoming the subject of pseudo-observation based on the presence or absence of interference from pulse B. Furthermore, if necessary, the light intensity ratio with pulse B is corrected according to the probability setting of the QRNG. (3) Optical control element: This is a means for controlling the polarization state and optical path of pulse A according to the output of the QRNG, thereby switching between a state in which interference with pulse B is possible and a state in which it is not. (4) Second optical pulse generating means: The first optical pulse generating means is a means for emitting pulse B by a physically or systematically independent light source, and is configured so that the pulse B interferes spatially and temporally with pulse A depending on the control state of the optical control element, and serves to perform pseudo-observation (observation without quantum contraction) of pulse A depending on the presence or absence of interference. In addition, the optical intensity ratio with pulse A is corrected as necessary according to the probability setting of QRNG. (5) Timing control device: A device that controls the timing so that the QRNG operates after the emission of Pulse A and Pulse B. (6) Control signal output device: A device that generates signals to control optical control elements based on the output results of the QRNG. (7) Interference detection means: This is an interference detection means (PD or OSA) that detects interference due to the interaction, particularly beats due to interference, in the region where pulse A and pulse B are assumed to be combined spatially and temporally. Depending on the presence or absence of interference, it is possible to verify whether pulse A was in an undetermined state in the reference system of pulse B.

[0010] With this configuration, the present invention makes it possible to verify the relative structure of observation problems in quantum mechanics through the presence or absence of interference phenomena when the object of observation and the observer are quantum separated.

[0011] In this device, a condition for interference to occur is that the polarization direction of pulse A and the polarization direction of pulse B must match. Therefore, the polarization direction of the second optical pulse generating means that emits pulse B is fixed in advance (for example, vertical polarization), and if the optical control element is a polarization control element, optical interference with pulse B occurs only when the polarization direction of pulse A is controlled to be vertical. If the optical control element is an optical path control element, the polarization direction of the first optical pulse generating means that emits pulse A is fixed in advance so that it interferes with pulse B, and interference occurs when the optical path for multiplexing with pulse B is selected by optical path control. Furthermore, by providing a frequency difference of approximately several GHz between the first and second optical pulse generating means, the occurrence of beats due to interference becomes clear. [Effects of the Invention]

[0012] According to the present invention, it is possible to interferometrically verify the "relative uncertainty" of a quantum state, i.e., the possibility that the determination of a quantum state occurs depending on the observer's frame of reference, using components separated in terms of observational systems.

[0013] In conventional delayed choice experiments, the object of observation and the interferer each consist of identical or entangled photons, which inevitably mixes the causal relationship between interference and observation (wave function collapse).

[0014] In this invention, pulse A and pulse B are separated in terms of the observation system, and each plays the role of the object of observation and the observer, so that observation based on the presence or absence of interference can be attempted, that is, observation without contraction can be attempted through non-destructive interferometric detection while the wave remains as a probability wave.

[0015] In particular, the optical state of pulse A is controlled based on a quantum random number, but even though the output result of the quantum random number is determined from the environmental system of the experimental equipment, it can be interpreted as being undetermined when the system of pulse B, which has not been observed from the environmental system, is used as the observation system.Therefore, the optical state of pulse A, which is linked to the output result of the quantum random number, can also be interpreted as being undetermined from the system of pulse B.

[0016] In this way, the present invention is configured so that the state of pulse A is uncertain from the perspective of pulse B, and its effect is observed only after the interference between pulses A and B, providing an experimental means to question the existence of a "probability wave-like entity" prior to observation through the observer's frame of reference. Furthermore, by linking the presence or absence of interference to a specific calculation result, it becomes possible to realize a new calculation method that mimics a quantum sorting structure in a classical calculation device.

[0017] Furthermore, since the present invention uses an optical pulse consisting of multiple photons, it is possible to use an OSA (optical spectrum analyzer) as an interference detection means in addition to a conventional PD (high-speed photodetector).

[0018] OSA obtains the wave signature of interference by observing the spectral structure (e.g., sidebands accompanying the beat) resulting from the minute frequency difference between the pulses.

[0019] This observation can be performed without specifying the path or polarization of the photon, and can be theoretically interpreted as a non-destructive observation method that does not involve the collapse of the wave function. Therefore, the use of OSA will be a more useful component in verifying the quantum uncertainty that is the subject of this invention.

[0020] The device of the present invention has an advantage not found in conventional technology in that it is capable of non-destructively obtaining traces of quantum probability waves that are not determined prior to observation through interference, by using a configuration that includes a quantum random number generator, an interference control optical system, and a PD or OSA.

[0021] Furthermore, this experimental device has the theoretical significance of enabling experimental verification of fundamental questions regarding quantum theory, such as: 1. Whether the contraction of quantum states is absolute or relative to the observation system can be empirically determined by the presence or absence of interference. 2. We propose a new quantum observation method that shows the existence of probability waves without performing observations involving contractions. 3. Even though independent light sources are used, it is possible to verify that the possibility of interference varies depending on the constructive conditions (common observation system information). 4. The presence or absence of quantum interference in coherent pulses can be observed nondestructively and statistically. 5. In the embodiment, the first and second optical pulse generating means are arranged separately and generate pulses with independent origins. By comparing this with a case in which pulses obtained from a single coherent light source are branched using a half mirror or the like, it becomes possible to compare the conditions for interference to occur and the observed results for both the common-origin system and the independent-origin system, making it possible to verify the true nature of quantum interference. 6. Even when interference detection fails in principle, it is possible to provide limited and supporting evidence for existing quantum theoretical interpretations such as the contraction hypothesis, environmental decoherence, and the necessity of entanglement.

[0022] Therefore, the present invention is not merely an interference experiment device, but has an extremely significant configuration that also serves as a verification device for quantum theory itself. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing the configuration of an interference experiment device for verifying quantum interference structures (Example 1). DETAILED DESCRIPTION OF THE INVENTION

[0024] As shown in FIG. 1, the device includes the following means: 1. QRNG (Quantum Random Number Generator) (1): Operates after a pulse is emitted and generates a probabilistic output value (e.g., 0 or 1). 2. First optical pulse generating means (2): Emits an optical pulse (pulse A). This is a coherent optical pulse due to subsequent interference, but if the optical control of the experimental device is polarization control, the polarization state is not fixed. 3. Optical control element (3): This is a means for controlling the optical state of pulse A according to the output of the QRNG (1), thereby switching between a state in which interference with pulse B is possible and a state in which it is not possible. For example, it switches between vertical polarization and horizontal polarization. 4. Second optical pulse generating means (4): Emits an optical pulse (pulse B). Due to subsequent interference, the optical pulse is a coherent optical pulse with a fixed polarization state. 5. Timing control device (5): This is a control device that instructs the emission of pulse A and pulse B and the start of QRNG(1) operation, and controls the timing so that QRNG(1) operates after the emission of pulse A and pulse B. 6. Control signal output device (6): A means for determining the control state of the optical control element (3) based on the output result of the QRNG (1). For example, if the optical control element (3) is a polarization control element, it determines whether the light is to be vertically or horizontally polarized based on the output result of the QRNG (1). 7. Interference detection means (7): An interference detection means (PD or OSA) that detects interference caused by the interaction of pulse A and pulse B in the area where they are expected to be combined, particularly beats due to interference. Depending on the presence or absence of interference, it is possible to verify whether pulse A was in an undetermined state in the reference system of pulse B.

[0025] In this embodiment, the first optical pulse generating means (2) and the second optical pulse generating means (4) are arranged almost parallel to the optical axis direction, but by slightly tilting their respective arrangement angles, only pulse A is passed through the optical control element, and then the combined pulses are sent to the interference detection means.

[0026] In this device, the timing control device (5) controls the timing so that the QRNG (1) operates after both pulses are emitted, and when a probabilistically determined numerical value is output from the QRNG (1), the control signal output device (6) receives this output and determines the control state of the optical control element (3), and controls the optical control element (3) accordingly.

[0027] In the device's environmental system, the random number output of QRNG(1) can be considered to be observed and determined at the moment it is output. In other words, if the environmental system is considered the observation system, the optical state of pulse A accompanying the output result of QRNG(1) can also be considered determined. However, if the system of pulse B, which has not yet been observed in the environmental system after QRNG(1) operation, is considered the observation system, we predict that even the optical state of pulse A accompanying QRNG(1) operation can be considered undetermined, and this invention is an experimental device for verifying this.

[0028] If the conjecture is correct, then even if the output of QRNG(1) is optically controlled in a way that does not cause interference as seen by us in the environment, interference may be detected by the interference detection means. This will realize a structure that can verify whether quantum uncertainty is maintained depending on the observation system.

[0029] The reason why not only pulse B but also pulse A is emitted before the operation of QRNG(1) is to align the timing of the combination of pulse A and pulse B, but also to increase the uncertainty of pulse A as seen by pulse B.

[0030] It is also considered meaningful to use the present invention to verify whether the experimental results change by shifting the emission timing of pulse A and pulse B.

[0031] Furthermore, if interference detection based on the "relative uncertainty" of the present invention is established, it is possible to use a classical computer in the control signal output device (6) to perform complex calculations according to the output results of the QRNG (1), and through optical control based on the results, selectively output only the correct answer from among the probabilistically generated calculation candidates through interference, thereby providing an architecture different from conventional quantum computers.

[0032] Thus, the present invention is of great theoretical and technological significance not only as a means of experimentally verifying the measurement problem in quantum mechanics, but also as a proposal for a new computational structure. [Example]

[0033] In this embodiment, using the basic configuration of the invention, a timing control device issues pulse emission instructions to a laser light source, which is the first optical pulse generating means (2), and a laser light source, which is the second optical pulse generating means (4), and immediately after the pulse emission, issues an operation instruction to the QRNG (1).

[0034] The polarization state of the second optical pulse generating means (4) is fixed to vertical polarization. The control signal output device controls the polarization control element (Pockels cell) (3) according to the signal 0 or 1 output from the QRNG (1), thereby controlling the polarization state of the pulse A emitted from the first optical pulse generating means (2) to be vertical or horizontal.

[0035] The combining means for pulse A and pulse B emits each pulse spatially parallel and at a small angle, and the optical paths are overlapped on the interference detection means. Fine adjustment is made by adjusting the relative arrangement (position) of the light sources so that they are combined spatially and temporally.

[0036] The presence or absence of interference is detected by an interference detection means (7), which is a PD (high-speed photodetector) or an OSA (optical spectrum analyzer).

[0037] In this example, pulse A and pulse B are emitted from independent laser light sources. However, in other embodiments, an optical pulse output from a single laser light source can be split into two paths using a beam splitter or half mirror, and optical path and polarization control can be applied to each path to attempt interference detection similar to that of this device. By comparing the interference patterns obtained by such a splitting method, it is possible to verify the origin and quantum significance of interference.

[0038] When the output (e.g., 0) of QRNG (1) at which interference occurs is set to an extremely low probability (e.g., 1 / 100), the intensity ratio of pulse A and pulse B is adjusted in advance to increase the S / N ratio of the interference. In this embodiment, the optical intensity of the first optical pulse generating means (2) (pulse A) is set relatively higher than that of the second optical pulse generating means (pulse B) according to the probability that QRNG (1) will emit a specific output. This setting is achieved by adjusting the laser drive current, an optical attenuation filter, or the like. In this way, it is possible to improve interference detection capabilities even when pulse A is a stochastic wave with a low probability.

[0039] When conducting the experiment, by using a high-speed computer (such as a microcomputer) for the timing control device (5) and the control signal output device (6), it becomes easy to configure the timing to be synchronized with the interference detection means (7). For example, by linking the output time of the QRNG (1) with the observation start trigger of the interference detection means (7), which is an OSA (optical spectrum analyzer), it is possible to improve the statistical detection efficiency.

[0040] The wavelength, intensity, time width, spatial diameter, etc. of the light pulse are not particularly limited as long as they are within the range that achieves the object of the present invention, and can be appropriately selected by a person skilled in the art.

[0041] In this embodiment, a beat signal due to interference can be detected by the OSA 1 by providing a frequency difference of several GHz between the first optical pulse generating means 2 and the second optical pulse generating means 4. Note that this frequency difference is not particularly limited as long as it is within a range in which the beat due to interference can be observed, and can be adjusted as appropriate by those skilled in the art. [Example]

[0042] The control signal output device (6) in this device is composed of a classical computer and performs the integrated generation of polarization control signals based on the output of the QRNG (1). This allows the entire device to function as a "system realizing quantum interference conditioned by classical computation."

[0043] In this embodiment, a method for obtaining the factor 13 (bit string 00001101) of the composite number 221 is shown as a calculation application.

[0044] First, assume that only the composite number 221 is given, and the factors are unknown. Odd numbers less than the square root (e.g., 3 to 13) are used as output candidates for QRNG(1), and a classical computer divides 221 by the output candidate. Once the classical computer outputs the correct divisor (13 in this case), it obtains the bit string of that number and, starting from the least significant bit, chooses whether or not to control pulse A to vertical polarization depending on the specified bit value (1 for interference, 0 for non-interference).

[0045] We determine whether interference has occurred for each bit of the classical computer's calculation result, while setting which bit position to output. By repeating this process the required number of times (e.g., four times), we obtain the bit string 13 (00001101) from the interference pattern corresponding to the correct answer (e.g., starting from the least significant bit, yes, no, yes, yes).

[0046] This is a sequential readout of calculation results using interference, and is a method of extracting information that differs from conventional quantum computers. [Industrial Applicability]

[0047] The present invention can be used as an experimental device for verifying observation structures in quantum mechanics, and is also expected to be applied in the computer field as a new information processing device using interference.

[0048] In particular, as a classical computing assistant system that mimics a quantum sorting structure, it can be used industrially in a wide range of fields, including security, high-speed calculations, and research applications. [Explanation of symbols]

[0049] 1 QRNG (Quantum Random Number Generator) 2. First optical pulse generating means (e.g., laser light source) 3 Optical control elements (e.g., Pockels cells) 4. Second optical pulse generating means (e.g., laser light source) 5 Timing control device 6 Control signal output device 7 Interference detection means (PD or OSA)

Claims

1. An interference experiment device for verifying the relative uncertainty of quantum states, (1) Quantum random number generation means, (2) first optical pulse generating means; (3) an optical control element for controlling the optical state (e.g., polarization state or optical path) of the pulse emitted from the first optical pulse generating means; (4) a second optical pulse generating means independent of the first optical pulse generating means; (5) a timing control device that controls the generation timing of the quantum random number generation means to be later than the pulse emission timing of the first optical pulse generation means and the pulse emission timing of the second optical pulse generation means; (6) a control signal output device that determines the control state of the optical control element based on the output result of the quantum random number generating means; (7) an interference detection means for detecting a beat signal based on the combined and interfering pulses emitted from the first optical pulse generating means and the second optical pulse generating means; and wherein the interference detection means can determine whether or not the pulse emitted from the first optical pulse generation means is in an undetermined state.

2. 2. The interference experimental apparatus according to claim 1, By using a classical computer as the control signal output device, the interference experimental device can be used as a calculation device that can selectively obtain calculation results by determining the candidate solution for a problem with a large number of candidate solutions (e.g., candidate divisors for factorization) based on the output result of a quantum random number generating means, and determining the control state of an optical control element according to the calculation result (e.g., correct answer) using the determined candidate solution.

3. 3. The interference experimental apparatus according to claim 1, An interference experimental device characterized in that the interference detection means is composed of an OSA (optical spectrum analyzer).

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