Role of anisotropic confining potential and elliptical driving in dynamics of a Ge hole qubit
arXiv:2409.03471 · doi:10.1088/1361-648X/adb927
Abstract
The squeezing of a Ge planar quantum dot enhances the Rabi frequency of electric dipole spin resonance by several orders of magnitude due to a strong Direct Rashba spin-orbit interaction in such geometries (Bosco et al 2021 Phys. Rev. B 104 115425). We investigate the geometric effect of an elliptical (squeezed) confinement and its interplay with the polarization of driving field in determining the Rabi frequency of a heavy-hole qubit in a planar Ge quantum dot. To calculate the Rabi frequency, we consider only the p-linear SOIs viz. electron-like Rashba, hole-like Rashba and hole-like Dresselhaus which are claimed to be the dominant ones by recent studies on planar Ge heterostructures. We derive approximate analytical expressions of the Rabi frequency using a Schrieffer-Wolff transformation for small SOI and driving strengths. Firstly, for an out-of-plane magnetic field with magnitude B, we get an operating region with respect to B, squeezing and polarization parameters where the qubit can be operated to obtain 'clean' Rabi flips. On and close to the boundaries of the region, the higher orbital levels strongly interfere with the two-level qubit subspace and destroy the Rabi oscillations, thereby putting a limitation on squeezing of the confinement. The Rabi frequency shows different behaviour for electron-like and hole-like Rashba SOIs. It vanishes for right (left) circular polarization in presence of purely electron-like (hole-like) Rashba SOI in a circular confinement. For both in- and out-of-plane magnetic fields, higher Rabi frequencies are achieved for squeezed configurations when the ellipses of polarization and the confinement equipotential have their major axes aligned but with different eccentricities. We also deduce a simple formula to calculate the effective heavy hole mass by measuring the Rabi frequencies using this setup.
References in corpus (43)
- Electron spin coherence exceeding seconds in high purity silicon
- Phonon-induced decay of the electron spin in quantum dots
- A four-qubit germanium quantum processor
- The germanium quantum information route
- Electric Dipole Induced Spin Resonance in Quantum Dots
- Spin decoherence of a heavy hole coupled to nuclear spins in a quantum dot
- Fast two-qubit logic with holes in germanium
- Rashba spin splitting in two-dimensional electron and hole systems
- Ge hole spin qubit
- Strong Spin-Orbit Interaction and Helical Hole States in Ge/Si Nanowires
- A single-hole spin qubit
- Electric Dipole Spin Resonance for Heavy Holes in Quantum Dots
- A singlet triplet hole spin qubit in planar Ge
- Low disordered, stable, and shallow germanium quantum wells: a playground for spin and hybrid quantum technology
- Ultrafast coherent control of a hole spin qubit in a germanium quantum dot
- 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
- Theory of Hole-Spin Qubits in Strained Germanium Quantum Dots
- Spin Splitting in Symmetrical SiGe Quantum Wells
- Optimal operation points for ultrafast, highly coherent Ge hole spin-orbit qubits
- Squeezed hole spin qubits in Ge quantum dots with ultrafast gates at low power
- Spin-orbit interactions in inversion-asymmetric 2D hole systems: a variational analysis
- Strong spin-orbit interaction and -factor renormalization of hole spins in Ge/Si nanowire quantum dots
- Isotope sensitive measurement of the hole-nuclear spin interaction in quantum dots
- Spin dynamics in a strongly driven system: very slow Rabi oscillations
- Spin-orbit splitting of valence subbands in semiconductor nanostructures
- Light effective hole mass in undoped Ge/SiGe quantum wells
- Recent advances in hole-spin qubits
- Genetic Design of Enhanced Valley Splitting towards a Spin Qubit in Silicon
- Hole spin driving by strain-induced spin-orbit interactions
- Spin-3/2 physics of semiconductor hole nanowires: Valence-band mixing and tunable interplay between bulk-material and orbital bound-state spin splittings
- Spin Decay in a Quantum Dot Coupled to a Quantum Point Contact
- Supercoupling between heavy-hole and light-hole states in self-assembled quantum dots
- Hole spin manipulation in inhomogeneous and non-separable electric fields
- Longitudinal and transverse electric field manipulation of hole spin-orbit qubits in one-dimensional channels
- Emergence of the strong tunable linear Rashba spin-orbit coupling of two-dimensional hole gases in semiconductor quantum
- Quantum control of hole spin qubits in double quantum dots
- Electrical operation of planar Ge hole spin qubits in an in-plane magnetic field
- Linear-in-momentum spin orbit interactions in planar Ge/GeSi heterostructures and spin qubits
- The emergent linear Rashba spin-orbit coupling offering the fast manipulation of hole-spin qubits in germanium
- Hyperfine coupling of hole and nuclear spins in symmetric GaAs quantum dots
- Photo-assisted spin transport in double quantum dots with spin-orbit interaction
- Photodriven germanium hole qubit