Valley-Free Silicon Fins Caused by Shear Strain

Abstract

Electron spins confined in silicon quantum dots are promising candidates for large-scale quantum computers. However, the degeneracy of the conduction band of bulk silicon introduces additional levels dangerously close to the window of computational energies, where the quantum information can leak. The energy of the valley states -- typically 0.1 meV -- depends on hardly controllable atomistic disorder and still constitutes a fundamental limit to the scalability of these architectures. In this work, we introduce designs of complementary metal-oxide-semiconductor (CMOS)-compatible silicon fin field-effect transistors that enhance the energy gap to noncomputational states by more than one order of magnitude. Our devices comprise realistic silicon-germanium nanostructures with a large shear strain, where troublesome valley degrees of freedom are completely removed. The energy of noncomputational states is therefore not affected by unavoidable atomistic disorder and can further be tuned in situ by applied electric fields. Our design ideas are directly applicable to a variety of setups and will offer a blueprint toward silicon-based large-scale quantum processors.

References in corpus (64)

• Silicon Quantum Electronics
• An addressable quantum dot qubit with fault-tolerant control fidelity
• A Two Qubit Logic Gate in Silicon
• A >99.9%-fidelity quantum-dot spin qubit with coherence limited by charge noise
• A programmable two-qubit quantum processor in silicon
• A CMOS silicon spin qubit
• Computing with spin qubits at the surface code error threshold
• Fast universal quantum control above the fault-tolerance threshold in silicon
• A Coherent Spin-Photon Interface in Silicon
• Universal control of a six-qubit quantum processor in silicon
• A four-qubit germanium quantum processor
• Strong spin-photon coupling in silicon
• Silicon quantum processor unit cell operation above one Kelvin
• Fidelity benchmarks for two-qubit gates in silicon
• Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting
• Scalable gate architecture for densely packed semiconductor spin qubits
• Shuttling a single charge across a one-dimensional array of silicon quantum dots
• Scaling silicon-based quantum computing using CMOS technology: State-of-the-art, Challenges and Perspectives
• A Crossbar Network for Silicon Quantum Dot Qubits
• Precision tomography of a three-qubit donor quantum processor in silicon
• A fault-tolerant addressable spin qubit in a natural silicon quantum dot
• A hole spin qubit in a fin field-effect transistor above 4 kelvin
• Valley Splitting Theory of SiGe/Si/SiGe Quantum Wells
• Valley splitting in strained silicon quantum wells
• A singlet triplet hole spin qubit in planar Ge
• A Reconfigurable Gate Architecture for Si/SiGe Quantum Dots
• Benchmarking Gate Fidelities in a Si/SiGe Two-Qubit Device
• Coherent electrical control of a single high-spin nucleus in silicon
• Quantum tomography of an entangled three-spin state in silicon
• Strong coupling between a photon and a hole spin in silicon
• Theory of Hole-Spin Qubits in Strained Germanium Quantum Dots
• Physical mechanisms of interface-mediated intervalley coupling in Si
• Conveyor-mode single-electron shuttling in Si/SiGe for a scalable quantum computing architecture
• A single hole spin with enhanced coherence in natural silicon
• Electrically Protected Valley-Orbit Qubits in Silicon
• Measurement of valley splitting in high-symmetry Si/SiGe quantum dots
• A shuttling-based two-qubit logic gate for linking distant silicon quantum processors
• Large, tunable valley splitting and single-spin relaxation mechanisms in a Si/Si${}_x$Ge${}_{1-x}$ quantum dot
• Squeezed hole spin qubits in Ge quantum dots with ultrafast gates at low power
• High Resolution Valley Spectroscopy of Si Quantum Dots
• Atomic fluctuations lifting the energy degeneracy in Si/SiGe quantum dots
• Resonantly driven singlet-triplet spin qubit in silicon
• Spin relaxation in a Si quantum dot due to spin-valley mixing
• Tunable singlet-triplet splitting in a few-electron Si/SiGe quantum dot
• SiGe quantum wells with oscillating Ge concentrations for quantum dot qubits
• Single-Spin Relaxation in a Synthetic Spin-Orbit Field
• Dynamics of hole singlet triplet qubits with large g-factor differences
• High fidelity state preparation, quantum control, and readout of an isotopically enriched silicon spin qubit
• Deformation potential extraction and computationally efficient mobility calculations in silicon from first principles
• Site-selective quantum control in an isotopically enriched 28Si/SiGe quadruple quantum dot
• Electron g-factor of valley states in realistic silicon quantum dots
• Hole spin driving by strain-induced spin-orbit interactions
• Detuning Axis Pulsed Spectroscopy of Valley-Orbital States in Si/SiGe Quantum Dots
• Two-qubit logic with anisotropic exchange in a fin field-effect transistor
• Dressed photon-orbital states in a quantum dot: Inter-valley spin resonance
• Electromagnetic control of valley splitting in ideal and disordered Si quantum dots
• Hole spin qubits in thin curved quantum wells
• Acoustic phonons and strain in core/shell nanowires
• Switching between relaxation hotspots and coldspots in disordered spin qubits
• Interface and electromagnetic effects in the valley splitting of Si quantum dots
• Microwave-frequency scanning gate microscopy of a Si/SiGe double quantum dot
• Spin-orbit enhancement in Si/SiGe heterostructures with oscillating Ge concentration
• Multiscale theory of valley splitting
• The generalized plane piezoelectric problem: Theoretical formulation and application to heterostructure nanowires

Cited by in corpus (8)

• Strategies for enhancing spin-shuttling fidelities in Si/SiGe quantum wells with random-alloy disorder
• Coupling conduction-band valleys in SiGe heterostructures via shear strain and Ge concentration oscillations
• Theory of Valley Splitting in Si/SiGe Spin-Qubits: Interplay of Strain, Resonances and Random Alloy Disorder
• Valley splitting by extended zone effective mass approximation incorporating strain in silicon
• Fabrication, characterization and mechanical loading of Si/SiGe membranes for spin qubit devices
• Micromagnet-free operation of electron spin qubits in Si/Si${}_{1-x}$Ge${}_x$ vertical double quantum dots
• Effects of valley splitting on resonant-tunneling readout of spin qubits
• Wide Electrical Tunability of the Valley Splitting in a Doubly gated Silicon-on-Insulator Quantum Well