Related papers: Variability of hole spin qubits in planar Germaniu…
Silicon hole quantum dots have been the subject of considerable attention thanks to their strong spin-orbit coupling enabling electrical control. The physics of silicon holes is qualitatively different from germanium holes and requires a…
Spin qubits defined by valence band hole states comprise an attractive candidate for quantum information processing due to their inherent coupling to electric fields enabling fast and scalable qubit control. In particular, heavy holes in…
We analyze a prototypical particle-in-a-box model for a hole spin qubit. This quantum dot is subjected to static magnetic and electric fields, and to a radio-frequency electric field that drives Rabi oscillations owing to spin-orbit…
Exchange coupled {\it spin} qubits in semiconductor nanostructures are shown to be vulnerable to dephasing caused by {\it charge noise} invariably present in the semiconductor environment. This decoherence of exchange gate by environmental…
Strong spin-orbit interactions make hole quantum dots central to the quest for electrical spin qubit manipulation enabling fast, low-power, scalable quantum computation. Yet it is important to establish to what extent spin-orbit coupling…
Hole qubits in germanium quantum dots are promising candidates for coherent control and manipulation of the spin degree of freedom through electric dipole spin resonance. We theoretically study the time dynamics of a single heavy-hole qubit…
Strong `spin'-orbit coupled one-dimensional hole gas is achievable in a Ge nanowire in the presence of a strong magnetic field. The strong magnetic field lifts the two-fold degeneracy in the hole subband dispersions, so that the effective…
We study Zeeman splitting of zone-center subband edges in a cylindrical hole wire subject to a magnetic field parallel to its axis. The g-factor turns out to fluctuate strongly as a function of wire-subband index, assuming values that…
Si/SiGe heterostructures on bulk Si substrates have been shown to host high fidelity electron spin qubits. Building a scalable quantum processor would, however, benefit from further improvement of critical material properties such as the…
Fluctuations of electric fields can change the position of a gate-defined quantum dot in a semiconductor heterostructure. In the presence of magnetic field gradient, these stochastic shifts of electron's wavefunction lead to fluctuations of…
Hole spin qubits are frontrunner platforms for scalable quantum computers because of their large spin-orbit interaction which enables ultrafast all-electric qubit control at low power. The fastest spin qubits to date are defined in long…
In this work we present a comprehensive theory of spin physics in planar Ge hole quantum dots in an in-plane magnetic field, where the orbital terms play a dominant role in qubit physics, and provide a brief comparison with experimental…
The spin-orbit interaction is the key element for electrically tunable spin qubits. Here we probe the effect of cubic Rashba spin-orbit interaction on mixing of the spin states by investigating singlet-triplet oscillations in a planar Ge…
The pseudospin of heavy-holes (HHs) confined in a semiconductor quantum dot (QD) represents a promising candidate for a fast and robust qubit. While hole spin manipulation by a classical electric field utilizing the Dresselhaus spin-orbit…
Semiconductor architectures hold promise for quantum information processing (QIP) applications due to their large industrial base and perceived scalability potential. Electron spins in silicon in particular may be an excellent architecture…
Electron spin qubits in Si/SiGe quantum wells are limited by the small and variable energy separation of the conduction band valleys. While sharp quantum well interfaces are pursued to increase the valley splitting energy deterministically,…
We identify the presence of monoatomic steps at the Si/SiGe or Si/SiO$_2$ interface as a dominant source of variations in the dephasing time of Si quantum dot (QD) spin qubits. First, using atomistc tight-binding calculations we show that…
We investigate the existence of linear-in-momentum spin-orbit interactions in the valence band of Ge/GeSi heterostructures using an atomistic tight-binding method. We show that symmetry breaking at the Ge/GeSi interfaces gives rise to a…
A scalable spin-based quantum processor requires a suitable semiconductor heterostructure and a gate design, with multiple alternatives being investigated. Characterizing such devices experimentally is a demanding task, with the full…
Hole spin qubits are rapidly emerging as the workhorse of semiconducting quantum processors because of their large spin-orbit interaction, enabling fast all-electric operations at low power. However, spin-orbit interaction also causes…