Pulse-gated quantum-dot hybrid qubit

Phys Rev Lett. 2012 Dec 21;109(25):250503. doi: 10.1103/PhysRevLett.109.250503. Epub 2012 Dec 20.

Abstract

A quantum-dot hybrid qubit formed from three electrons in a double quantum dot has the potential for great speed, due to the presence of level crossings where the qubit becomes chargelike. Here, we show how to exploit the level crossings to implement fast pulsed gating. 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 the gates are fast (subnanosecond) and can achieve high fidelities.