Hole-phonon interactions in quantum dots: Effects of phonon confinement and encapsulation materials on spin-orbit qubits

Abstract

Spin-phonon interactions are one of the mechanisms limiting the lifetime of spin qubits made in semiconductor quantum dots. At variance with other mechanisms such as charge noise, phonons are intrinsic to the device and can hardly be mitigated. They set, therefore fundamental limits to the relaxation time of the qubits. Here we introduce a general framework for the calculation of the spin (and charge) transition rates induced by bulk (3D) and strongly confined 1D or 2D phonons. We discuss the particular case of hole spin-orbit qubits described by the 6 bands kp model. We next apply this theory to a hole qubit in a silicon-on-insulator device. We show that spin relaxation in this device is dominated by a band mixing term that couples the holes to transverse acoustic phonons through the valence band deformation potential d, and optimize the bias point and magnetic field orientation to maximize the number of Rabi oscillations Q that can be achieved within on relaxation time T1. Despite the strong spin-orbit coupling in the valence band, the phonon-limited Q can reach a few tens of thousands. We next explore the effects of phonon confinement in 1D and 2D structures, and the impact of the encapsulation materials on the relaxation rates. We show that the spin lifetimes can depend on the structure of the device over micrometer-long length scales and that they improve when the materials around the qubit get harder. Phonon engineering in semiconductor qubits may therefore become relevant once the extrinsic sources of relaxation have been reduced.

arXiv comment17 pages, 10 figures + 10 pages supplementary information

References in corpus (42)

• Quantum Computation with Quantum Dots
• Introduction to Quantum Noise, Measurement and Amplification
• 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 single-atom electron spin qubit in silicon
• A programmable two-qubit quantum processor in silicon
• Electron spin coherence exceeding seconds in high purity silicon
• A CMOS silicon spin qubit
• 1/f noise: implications for solid-state quantum information
• Electrically driven single electron spin resonance in a slanting Zeeman field
• Quantum CNOT Gate for Spins in Silicon
• Electrical control of a long-lived spin qubit in a Si/SiGe quantum dot
• Phonon-induced decay of the electron spin in quantum dots
• Comparison of two methods for describing the strain profiles in quantum dots
• Fidelity benchmarks for two-qubit gates in silicon
• Spin relaxation and decoherence of holes in quantum dots
• Fast two-qubit logic with holes in germanium
• Ge hole spin qubit
• A fault-tolerant addressable spin qubit in a natural silicon quantum dot
• Observation of extremely slow hole spin relaxation in self-assembled quantum dots
• Strong Spin-Orbit Interaction and Helical Hole States in Ge/Si Nanowires
• A single-hole spin qubit
• Spin relaxation and anticrossing in quantum dots: Rashba versus Dresselhaus spin-orbit coupling
• Electrical spin driving by $g$-matrix modulation in spin-orbit qubits
• Gate-reflectometry dispersive readout and coherent control of a spin qubit in silicon
• Spin lifetime and charge noise in hot silicon quantum dot qubits
• Direct Rashba spin-orbit interaction in Si and Ge nanowires with different growth directions
• Circuit QED with Hole-Spin Qubits in Ge/Si Nanowire Quantum Dots
• Electrically driven electron spin resonance mediated by spin-valley-orbit coupling in a silicon quantum dot
• Direct Observation of Acoustic Phonon Confinement in Free-Standing Semiconductor Nanowires
• Relaxation of excited spin, orbital, and valley qubit states in single electron silicon quantum dots
• Relaxation of hole spins in quantum dots via two-phonon processes
• Spin relaxation in a Si quantum dot due to spin-valley mixing
• Electrical manipulation of semiconductor spin qubits within the g-matrix formalism
• Tunable g factor and phonon-mediated hole spin relaxation in Ge/Si nanowire quantum dots
• Hole spin relaxation in semiconductor quantum dots
• Simple model for electrical hole spin manipulation in semiconductor quantum dots: Impact of dot material and orientation
• Phonon-Mediated Decay of Singlet-Triplet Qubits in Double Quantum Dots
• All-electrical manipulation of silicon spin qubits with tunable spin-valley mixing
• Phonon-induced decoherence of a charge quadrupole qubit

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• Longitudinal and transverse electric field manipulation of hole spin-orbit qubits in one-dimensional channels
• Electrical operation of planar Ge hole spin qubits in an in-plane magnetic field
• Hole spin qubits in thin curved quantum wells
• Light-Hole Gate-Defined Spin-Orbit Qubit
• Electrical control of the hole spin qubit in Si and Ge nanowire quantum dots
• Electrical operation of hole spin qubits in planar MOS silicon quantum dots
• Modelling of spin decoherence in a Si hole qubit perturbed by a single charge fluctuator
• Dephasing of planar Ge hole spin qubits due to 1/$\text{f}$ charge noise
• Dressed basis sets for the modeling of exchange interactions in double quantum dots
• Spin properties in droplet epitaxy-grown telecom quantum dots
• Anomalous zero-field splitting for hole spin qubits in Si and Ge quantum dots
• Phonon-induced frequency shift in semiconductor spin qubits