Gate-Induced Charge Layer for Spin Readout in Silicon
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Solution Overview
Problem
Current technologies face challenges in achieving coherent control and readout of the electron or hole spin of a single dopant in silicon, particularly in designing a compact and scalable quantum computing architecture that is compatible with industry MOS technology and effective in operating within a wide frequency range.
Innovation Solution
An electronic device comprising a silicon substrate with ohmic contact regions, insulating layers, barrier gates forming a Single Electron Transistor (SET), and a fourth gate acting as an Electron Spin Resonance (ESR) line for controlling the spin of a single dopant, with the SET island serving as a charge reservoir for spin detection, enabling flexible and scalable quantum computing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a separate charge reservoir and ESR control structure are used, then spin control and readout functionality is achieved, but device complexity and footprint increase
Solution Approach 1:
The patent combines the charge reservoir and ESR control functions into a single gate structure. The third gate serves dual purposes: it generates the gate-induced charge layer (acting as charge reservoir) and provides ESR control for spin manipulation. This merging eliminates the need for separate reservoir and control structures, reducing device complexity while maintaining full functionality.
Solution Approach 2:
The third gate is designed to perform multiple functions simultaneously: it induces the charge layer in the substrate, controls the charge tunneling to the SET island, and provides ESR control for spin manipulation. This multi-functional design reduces the number of components needed and simplifies the overall device architecture.
2Ease of manufacture
If industry MOS technology is used, then manufacturing compatibility and scalability are improved, but achieving precise single dopant control and readout becomes more difficult
Solution Approach 1:
The patent creates a highly localized electric field and charge induction region directly beneath the third gate, concentrating the effect on a single dopant atom. The gate-induced charge layer is confined to a small region under the gate, enabling precise control and detection of individual dopant spin states using standard MOS fabrication techniques.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for precise control and readout of the spin state of a single dopant, overcoming the limitations of previous architectures by integrating charge reservoir and ESR functions within a compact MOS device, enhancing scalability and compatibility with industry standards, and enabling efficient spin-dependent tunnelling and measurement.
Implementation Method 1
A third gate 28 overlying both the first and second barrier gates 20, 22 but insulated from them, the third gate 28 being able to generate a gate-induced charge layer (GICL) 29 in the substrate beneath it
Implementation Method 2
A fourth gate 52 in close proximity of a single dopant atom 44, the dopant atom 44 being encapsulated in the substrate outside the region of the GICL but close enough to allow readout of the electron or hole spin by detecting spin-dependent charge tunnelling between the dopant atom and the SET island under the control of the potential of the fourth gate
Implementation Method 3
Wherein, either the third or fourth gate also serve as an Electron Spin Resonance (ESR) line to control the spin of the single electron or hole of the dopant
Data Source
Figure 1(a)~1(e)
Figure 2(a)~2(d)
Figure 3(a)~3(b)
AI summary
This invention concerns an electronic device for the control and readout of the electron or hole spin of a single dopant in silicon. The device comprises a silicon substrate in which there are one or more ohmic contact regions. An insulating region on top of the substrate. First and second barrier gates spaced apart to isolate a small region of charges to form an island of a Single Electron Transistor (SET). A third gate overlying both the first and second barrier gates, but insulated from them, the third gate being able to generate a gate-induced charge layer (GICL) in the substrate beneath it. A fourth gate in close proximity to a single dopant atom, the dopant atom being encapsulated in the substrate outside the region of the GICL but close enough to allow spin-dependent charge tunnelling between the dopant atom and the SET island under the control of gate potentials, mainly the fourth gate. In use either the third or fourth gate also serve as an Electron Spin Resonance (ESR) line to control the spin of the single electron or hole of the dopant atom. In a further aspect it concerns a method for using the device.