Coulomb interaction and valley-orbit coupling in Si quantum dots

Abstract

The valley-orbit coupling in a few-electron Si quantum dot is expected to be a function of its occupation number N. We study the spectrum of multivalley Si quantum dots for 2 <= N <= 4, showing that, counterintuitively, electron-electron interaction effects on the valley-orbit coupling are negligible. For N=2 they are suppressed by valley interference, for N=3 they vanish due to spinor overlaps, and for N = 4 they cancel between different pairs of electrons. To corroborate our theoretical findings, we examine the experimental energy spectrum of a few-electron metal-oxide-semiconductor quantum dot. The measured spin-valley state filling sequence in a magnetic field reveals that the valley-orbit coupling is definitively unaffected by the occupation number.

References in corpus (13)

• Silicon Quantum Electronics
• Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting
• Spin-echo of a single electron spin in a quantum dot
• Valley Polarization in Si(100) at Zero Magnetic Field
• Excited-state spectroscopy on a nearly-closed quantum dot via charge detection
• Electron spin phase relaxation of phosphorus donors in nuclear spin enriched silicon
• Spin and valley-orbit splittings in SiGe/Si heterostructures
• Decoherence induced by anisotropic hyperfine interaction in Si spin qubits
• Hubbard model description of silicon spin qubits: charge stability diagram and tunnel coupling in Si double quantum dots
• Spin filling of valley-orbit states in a silicon quantum dot
• Orbital and valley state spectra of a few-electron silicon quantum dot
• Singlet-Triplet Relaxation in Two-electron Silicon Quantum Dots
• Valley splitting of Si/SiGe heterostructures in tilted magnetic fields

Cited by in corpus (12)

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• Strong electron-electron interactions in Si/SiGe quantum dots
• Hybrid spin and valley quantum computing with singlet-triplet qubits
• Modelling semiconductor spin qubits and their charge noise environment for quantum gate fidelity estimation
• Charge State Hysteresis in Semiconductor Quantum Dots
• Effects of Interface Steps on the Valley Orbit coupling in a Si/SiGe quantum dot
• Two-body Wigner molecularization in asymmetric quantum dot spin qubits
• Impact of valley phase and splitting on readout of silicon spin qubits
• Prediction of the spin triplet two-electron quantum dots in Si: towards controlled quantum simulations of magnetic systems
• Signatures of Valley Kondo Effect in Si/SiGe Quantum Dots
• Impact of the valley orbit coupling on exchange gate for spin qubits in silicon quantum dots
• On the validity of microscopic calculations of double-quantum-dot spin qubits based on Fock-Darwin states