Skip to content
Preprint

Noise-Robust Spin-Orbit Qubit in Germanium Holes via p-Orbital Encoding

Aug 2026 · 0 citations · 5 references
Physics

Abstract

Germanium hole spin qubits are a leading platform for semiconductor quantum computation due to their strong spin-orbit coupling, all-electrical operability, and absence of valley degeneracy. A central obstacle is charge noise, which couples to the qubit through the same spin-orbit interaction that enables fast electrical control. In this work, we propose a new operational mode of a three-hole quantum dot in a planar Ge/SiGe heterostructure, modeled within a four-band Luttinger-Kohn--Bir-Pikus framework: a spin-$p$-orbital (SpO) qubit encoded in the $p$-shell of the topmost hole. We characterize charge noise sweet spots in the parameter space of electrostatic confinement and magnetic field, and estimate that relaxation rates of the SpO qubit are comparable to those of spin qubits hosted in single holes. We then design and optimize an all-electrical Landau-Zener state-transfer protocol that induces logical qubit state transitions without microwave driving, and we show that the quadrupole-quadrupole Coulomb interaction between neighboring dots enables fast two-qubit entangling gates operated by adiabatic shuttling.

View source

Similar papers

Preprint Aug 2026

Engineering two-qubit gates via anisotropic exchange in germanium spin qubits

Germanium hole spin qubits are a promising and versatile platform for quantum computation and simulation. In this system, strong spin-orbit interaction (SOI) renders the single-qubit $g$-tensor anisotropic and electrically tunable, enabling operational sweet spots with reduced noise sensitivity. SOI also transforms the...

L. Massai, Bence Het'enyi, E. G. Kelly et al. · 2 citations
Sep 2026

In-plane optimal qubit operation with control fidelities exceeding 99%

Hole spin qubits based on semiconductor quantum dots are promising for building future large-scale quantum computers owing to their all-electrical manipulation. However, abundant physical mechanisms of valence band holes lead to anisotropic qubit properties. There is an opportunity to prolong the coherence time and ach...

Yu-Chen Zhou, Zhen-Zhen Kong, Rong-Long Ma et al. · 0 citations
Preprint Aug 2026

Superfast hole spin qubits enabled by uniaxial strain-boosted spin-orbit coupling

Two-dimensional (2D) electron/hole gases confined in semiconductor heterostructures suffer from weak Rashba spin-orbit coupling (SOC) for manipulating spin degreee of freedom via an electric rather than a magnetic field. Here, we show that complementary metal-oxide-semiconductor technology-accessible strain could subst...

Yixin Wang, Yang Liu, Shan Guan et al. · 0 citations
Preprint Aug 2026

Coherence protection of a silicon hole spin qubit with phase-modulated microwave driving

Hole spins in silicon quantum dots are a promising platform for quantum computing due to their strong intrinsic spin-orbit coupling (SOC), which enables fast, all-electrical control. However, this coupling also increases their susceptibility to charge noise, thereby limiting coherence times. Moreover, holes in silicon...

S. I. Ibad, Yusuke Sato, T. Kuno et al. · 0 citations
Preprint Sep 2026

Quantum Gates Built on a Spin Qubit and a Kitaev Parity Qubit

Spin is typically traced out in the description of quantum-dot-based Kitaev chains to simplify the construction of Majorana fermions. Yet the intrinsic spin structure of poor-man's Majorana modes in minimal Kitaev chains under finite Zeeman fields offers a natural interface for the Kitaev parity qubit to interact with...

Zhi-Hai Liu, Jiang Zhang, G. Long et al. · 0 citations
Preprint Aug 2026

Switchable heavy-hole/light-hole spin qubit

Compressively strained Ge quantum wells in planar SiGe/Ge heterostructures are the state-of-the-art platform for hole spin qubits. While they exhibit robust coherence times, they possess weak intrinsic spin-orbit interaction (SOI) due to the heavy-hole (HH) character of the wavefunction. Recently, light-hole (LH) qubit...

Z. György, D. Miserev, J. Klinovaja et al. · 0 citations

We use cookies to run the site and, with your consent, for analytics and to show ads. See our Cookie Policy.