Quantum control of hole spin qubits in double quantum dots

TL;DR

This paper demonstrates a fast, robust method for controlling hole spin qubits in double quantum dots using adiabatic driving, achieving high-fidelity universal quantum gates suitable for quantum computing.

Contribution

It introduces a novel fast adiabatic control protocol for hole spin qubits that surpasses traditional methods in fidelity and noise robustness.

Findings

Achieved >99% fidelity for single and two-qubit gates.

Reduced charge noise significantly during qubit manipulation.

Demonstrated universal quantum gate set with hole spins.

Abstract

Hole spin qubits in semiconductor quantum dots (QDs) are promising candidates for quantum information processing due to their weak hyperfine coupling to nuclear spins, and to the strong spin-orbit coupling which allows for rapid operation time. We propose a coherent control on two heavy-hole spin qubits in a double QD by a fast adiabatic driving protocol, which helps to achieve higher fidelities than other experimentally commonly used protocols as linear ramping, $\pi$-pulses or Landau-Zener passages. Using fast quasiadiabatic driving via spin-orbit coupling, it is possible to reduce charge noise significantly for qubit manipulation and achieve high robustness for the qubit initialization. We also implement one and two-qubit gates, in particular, NOT, CNOT, and SWAP-like gates, of hole spins in a double QD achieving fidelities above $99\%$, exhibiting the capability of hole spins to implement universal gates for quantum computing.