Pulse-gated quantum dot hybrid qubit

TL;DR

This paper introduces a pulsed gating scheme for a quantum dot hybrid qubit that leverages level crossings to enable fast, high-fidelity quantum gates using simpler dc control sequences.

Contribution

It presents a novel pulsed gating approach that exploits level crossings in a quantum dot hybrid qubit, simplifying gate implementation and achieving high fidelities.

Findings

Sub-nanosecond gate times achieved

High fidelities demonstrated for control sequences

Simpler dc gates compared to previous ac methods

Abstract

A quantum dot hybrid qubit formed from three electrons in a double quantum dot has the potential for great speed, due to presence of level crossings where the qubit becomes charge-like. Here, we show how to take full advantage of the level crossings in a pulsed gating scheme, which decomposes the spin qubit into a series of charge transitions. We develop one and two-qubit dc quantum gates that are simpler than the previously proposed ac gates. We obtain closed form solutions for the control sequences and show that these sub-nanosecond gates can achieve high fidelities.