A simple, robust, and scalable quantum logic gate with quantum dot cavity QED systems

TL;DR

This paper introduces a robust, scalable quantum logic gate using quantum dot cavity QED systems that operates deterministically without measurement, suitable for integration on semiconductor chips.

Contribution

It presents a novel method for a deterministic, measurement-free controlled-phase gate in quantum dot systems, robust to inhomogeneity and compatible with modest-Q cavities.

Findings

Gate is robust to quantum dot inhomogeneity

Requires only a single laser pulse

Performance degrades with spontaneous emission and cavity loss

Abstract

We present a method to enact a deterministic, measurement-free, optically generated controlled-phase gate on two qubits defined by single electrons trapped in large-area quantum dots in a planar microcavity. This method is robust to optical quantum dot inhomogeneity, requires only a modest-$Q$ planar cavity, employs only a single laser pulse, and allows the integration of many entangled qubits on one semiconductor chip. We present the gate in the contexts of both adiabatic evolution and geometric phases, and calculate the degradation of performance in the presence of both spontaneous emission and cavity loss.