Exchange coupling in silicon quantum dots: Theoretical considerations for quantum computation

Abstract

We study exchange coupling in Si double quantum dots, which have been proposed as suitable candidates for spin qubits due to their long spin coherence times. We discuss in detail two alternative schemes which have been proposed for implementing spin qubits in quantum dots. One scheme uses spin states in a single dot and the interdot exchange coupling controls interactions between unbiased dots. The other scheme employs the singlet and triplet states of a biased double dot as the two-level system making up the qubit and exchange controls the energy splitting of the levels. Exchange in these two configurations depends differently on system parameters. Our work relies on the Heitler-London approximation and the Hund-Mulliken molecular orbital method. The results we obtain enable us to investigate the sensitivity of the system to background charge fluctuations and determine the conditions under which optimal spots, at which the influence of the charge noise is minimized, may exist in Si double quantum dot structures.

18 pages, 12 figures

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Cited by in corpus (71)

• Silicon Quantum Electronics
• Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting
• Charge-noise spectroscopy of Si/SiGe quantum dots via dynamically-decoupled exchange oscillations
• Interface roughness, valley-orbit coupling and valley manipulation in quantum dots
• Generic Hubbard model description of semiconductor quantum dot spin qubits
• Quantum dot spin qubits in Silicon: Multivalley physics
• Intervalley coupling for interface-bound electrons in silicon: An effective mass study
• Multivalley effective mass theory simulation of donors in silicon
• Dynamical decoupling noise spectroscopy at an optimal working point of a qubit
• Hubbard model description of silicon spin qubits: charge stability diagram and tunnel coupling in Si double quantum dots
• Impurity effects on semiconductor quantum bits in coupled quantum dots
• Theory of Single Electron Spin Relaxation in Si/SiGe Lateral Coupled Quantum Dots
• Network architecture for a topological quantum computer in silicon
• Quantum theory of the charge stability diagram of semiconductor double quantum dot systems
• Exchange coupling in a linear chain of three quantum-dot spin qubits in silicon
• Two-spin dephasing by electron-phonon interaction in semiconductor double quantum dots
• Spin State Transfer in Laterally Coupled Quantum Dot Chains with Disorders
• Interplay of charge noise and coupling to phonons in adiabatic electron transfer between quantum dots
• Singlet-triplet relaxation in multivalley silicon single quantum dots
• Hyperfine interaction induced dephasing of coupled spin qubits in semiconductor double quantum dots
• Bounds to electron spin qubit variability for scalable CMOS architectures
• Noise-compensating pulses for electrostatically controlled silicon spin qubits
• A many-electron tight binding method for the analysis of quantum dot systems
• Configuration interaction calculations of the controlled phase gate in double quantum dot qubits
• Theory of Spin Relaxation in Two-Electron Lateral Coupled Si/SiGe Quantum Dots
• Impact of valley phase and splitting on readout of silicon spin qubits
• Transporting a single-spin qubit through a double quantum dot
• Coherent electrical rotations of valley states in Si quantum dots using the phase of the valley-orbit coupling
• Read-out and Dynamics of the Qubit Built on Three Quantum Dots
• Negative exchange interactions in coupled few-electron quantum dots
• Spin-orbit-coupled quantum memory of a double quantum dot
• Theory of barrier vs tilt exchange gate operations in spin-based quantum computing
• Charge-noise tolerant exchange gates of singlet-triplet qubits in asymmetric double quantum dots
• Leakage and sweet spots in triple-quantum-dot spin qubits: A molecular-orbital study
• Singlet-triplet relaxation in SiGe/Si/SiGe double quantum dots
• Interplay of exchange and superexchange in triple quantum dots
• Suppression of charge noise using barrier control of a singlet-triplet qubit
• Voltage controlled exchange energies of a two electron silicon double quantum dot with and without charge defects in the dielectric
• Low-noise conditional operation of singlet-triplet coupled quantum dot qubits
• Measurement of tunnel coupling in a Si double quantum dot based on charge sensing
• Dynamically corrected gates in silicon singlet-triplet spin qubits
• Intrinsic and extrinsic origins of low-frequency noise in GaAs/AlGaAs Schottky-gated nanostructures
• Implications of Electronics Constraints for Solid-State Quantum Error Correction and Quantum Circuit Failure Probability
• Influence of confining potentials on the exchange coupling in double quantum dots
• Extended orbital modeling of spin qubits in double quantum dots
• Energy spectra of three electrons in Si/SiGe single and vertically coupled double quantum dots
• Interacting Two-Level Systems as a Source of 1/f Charge Noise in Quantum Dot Qubits
• Low-Dissipation Data Bus via Coherent Quantum Dynamics
• A proposed spin qubit CNOT gate robust against noisy coupling
• Electric control of tunneling energy in graphene double dots
• Tunable charge qubit based on barrier-controlled triple quantum dots
• Coherent transfer of singlet-triplet qubit states in an architecture of triple quantum dots
• Energy spectra of three electrons in SiGe/Si/SiGe laterally coupled triple quantum dots
• Path integral simulation of exchange interactions in CMOS spin qubits
• Dynamical second-order noise sweetspots in resonantly driven spin qubits
• Robust entangling gate for capacitively coupled few-electron singlet-triplet qubits
• Energy spectrum, exchange interaction and gate crosstalk in a pair of double-quantum-dot system: a molecular orbital calculation
• A robust operating point for capacitively coupled singlet-triplet qubits
• Two-qubit logical operations in three quantum dots system
• Computational Assessment of Silicon Quantum Gate Based on Detuning Mechanism for Quantum Computing
• Universal control of superexchange in linear triple quantum dots with an empty mediator
• Bardeen's tunneling theory applied to intraorbital and interorbital hopping integrals between dopants in silicon
• Rapid adiabatic gating for capacitively coupled quantum dot hybrid qubits without barrier control
• Spin Hot Spots in Single-Electron GaAs-based Quantum Dots
• Performance Assessment of Resonantly Driven Silicon Two-Qubit Quantum Gate
• On the validity of microscopic calculations of double-quantum-dot spin qubits based on Fock-Darwin states
• Impact of the valley orbit coupling on exchange gate for spin qubits in silicon quantum dots
• The effects of alloy disorder on strongly-driven flopping mode qubits in Si/SiGe
• Inter- and intra-band Coulomb interactions between holes in silicon nanostructures
• Limitations on the maximal level of entanglement of two singlet-triplet qubits in GaAs quantum dots
• Electron readout contrast enhancement in the parallel nuclear regime of an exchange-coupled donor spin qubit system