Related papers: Hole spin splitting in a Ge quantum dot with finit…
Hole spin qubits in planar Ge heterostructures are one of the frontrunner platforms for scalable quantum computers. In these systems, the spin-orbit interactions permit efficient all-electric qubit control. We propose a minimal design…
The magnetic properties of hole quantum dots in Ge are sensitive to their shape due to the interplay between strong spin-orbit coupling and confinement. We show that the split-off band, surrounding SiGe layers, and hole-hole interactions…
We theoretically investigate the properties of holes in a Si$_{x}$Ge$_{1-x}$/Ge/ Si$_{x}$Ge$_{1-x}$ quantum well in a perpendicular magnetic field that make them advantageous as qubits, including a large ($>$100~meV) intrinsic splitting…
We theoretically investigate hole spins confined in a gate-defined quantum dot (QD) embedded in GeSn/Ge/GeSn quantum well (QW) structure. Owing to the tensile strain in the Ge layer, the system effectively realizes a light-hole qubit. We…
Even as today's most prominent spin-based qubit technologies are maturing in terms of capability and sophistication, there is growing interest in exploring alternate material platforms that may provide advantages, such as enhanced qubit…
Single holes confined in semiconductor quantum dots are a promising platform for spin qubit technology, due to the electrical tunability of the $g$-factor of holes. However, the underlying mechanisms that enable electric spin control remain…
Hole spin qubits in quasi one-dimensional structures are a promising platform for quantum information processing because of the strong spin-orbit interaction (SOI). We present analytical results and discuss device designs that optimize the…
We implement silicon quantum dot devices with two layers of gate electrodes using a self-alignment technique, which allows for ultra-small gate lengths and intrinsically perfect layer-to-layer alignment. In a double quantum dot system, we…
Quantum spin Hall insulators, recently realized in HgTe/(Hg,Cd)Te quantum wells, support topologically protected, linearly dispersing edge states with spin-momentum locking. A local magnetic exchange field can open a gap for the edge…
The usual models for electrical spin manipulation in semiconductor quantum dots assume that the confinement potential is separable in the three spatial dimensions and that the AC drive field is homogeneous. However, the electric field…
Spin qubits are typically operated in the lowest orbital of a quantum dot to minimize interference from nearby states. In valence-band hole systems, strong spin-orbit coupling links spin and orbital degrees of freedom, strongly influencing…
For a nanowire quantum dot with the confining potential modeled by both the infinite and the finite square wells, we obtain exactly the energy spectrum and the wave functions in the strong spin-orbit coupling regime. We find that regardless…
Holes in cubic semiconductors have effective spin 3/2 and very strong spin orbit interaction. Due to these factors properties of hole bound states are highly unusual. We consider a single hole bound by a spherically symmetric potential,…
We have studied theoretically the effect of a tuneable lateral confinement on two-dimensional hole systems realised in III-V semiconductor heterostructures. Based on the 4x4 Luttinger description of the valence band, we have calculated…
In the presence of spin-orbit coupling, quantum models for semiconductor materials are generally not exactly solvable. As a result, understanding of the strong spin-orbit coupling effects in these systems remains poor. Here we develop an…
Among recent proposals for next-generation, non-charge-based logic is the notion that a single electron can be trapped and its spin can be manipulated through the application of gate potentials. In this paper, we present numerical…
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…
Gate geometry and bias asymmetry can be used to engineer spin dynamics in gate-defined Ge hole quantum dots by reshaping the confinement potential and driving transitions between distinct confinement regimes. In this work, we show that…
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 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…