Optical Manipulation of Quantum Dot Electron Spin Qubits Using Microcavity Quantum Well Exciton-Polaritons

TL;DR

This paper proposes a new quantum dot qubit system utilizing exciton-polaritons in quantum wells, achieving scalable gates and measurement with enhanced interaction and speed through polariton traps and hybrid control methods.

Contribution

It introduces a novel system design with polariton traps that significantly improve interaction strength and gate speed, along with a hybrid optical-microwave one-qubit gate.

Findings

Polariton traps enhance quantum-dot--quantum-well interaction by 10 times.

Two-qubit gates are 100 times faster due to improved interaction.

The system supports scalable one- and two-qubit operations with single-shot measurement.

Abstract

In this paper we introduce and analyze a new system design for quantum-dot-based qubits that simultaneously supports scalable one-qubit and two-qubit gates, and single-shot qubit measurement. All three key processes (one-qubit gates, two-qubit gates, and qubit measurement) rely on the interaction between the electron in each quantum dot and exciton-polaritons formed in a quantum well situated near the quantum dots. A key novel feature of our proposed system is the use of polariton traps, which we show enhances the quantum-dot--quantum-well interaction by a factor of 10 and consequently results in $100 \times$ faster two-qubit gates. We also introduce a novel one-qubit gate that is based on a combination of optical and microwave control, which is supported in the same device and system configuration as the other operations, in contrast to the conventional one-qubit gate that is based on all-optical control.