Antisite defect qubits in monolayer transition metal dichalcogenides

TL;DR

This paper demonstrates that antisite defects in 2D transition metal dichalcogenides can serve as controllable, room-temperature solid-state spin qubits, identified through atomistic simulations and characterized by optical transitions and intersystem crossing.

Contribution

It introduces antisite defects in 2D TMDs as a new class of stable, optically addressable spin qubits suitable for scalable quantum information applications.

Findings

Identified neutral antisite defects with deep in-gap states in TMDs.

Demonstrated optical transitions and intersystem crossing for defect qubits.

Proposed WS2 antisite defect as a stable qubit platform.

Abstract

Being atomically thin and amenable to external controls, two-dimensional (2D) materials offer a new paradigm for the realization of patterned qubit fabrication and operation at room temperature for quantum information sciences applications. Here we show that the antisite defect in 2D transition metal dichalcogenides (TMDs) can provide a controllable solid-state spin qubit system. Using high-throughput atomistic simulations, we identify several neutral antisite defects in TMDs that lie deep in the bulk band gap and host a paramagnetic triplet ground state. Our in-depth analysis reveals the presence of optical transitions and triplet-singlet intersystem crossing processes for fingerprinting these defect qubits. As an illustrative example, we discuss the initialization and readout principles of an antisite qubit in WS2, which is expected to be stable against interlayer interactions in a multilayer structure for qubit isolation and protection in future qubit-based devices. Our study opens a new pathway for creating scalable, room-temperature spin qubits in 2D TMDs.