Substrate-controlled dynamics of spin qubits in low dimensional van-der-Waals materials

TL;DR

This paper provides a theoretical analysis of how substrate properties influence the coherence times of spin qubits in 2D van-der-Waals materials, highlighting the potential for engineering longer coherence in quantum devices.

Contribution

It introduces a model linking substrate composition and thickness to spin qubit decoherence, offering strategies to optimize coherence times in 2D quantum systems.

Findings

Coherence time depends on host and environment interactions.

Encapsulation can be engineered to enhance qubit coherence.

Quantum sensors can probe nuclear bath dynamics in 2D materials.

Abstract

We report a theoretical study of the coherence dynamics of spin qubits in two-dimensional materials (2DMs) and van-der-Waals heterostructures, as a function of the host thickness and the composition of the surrounding environment. We focus on MoS$_2$ and WS$_2$, two promising systems for quantum technology applications, and we consider the decoherence arising from the interaction of the spin qubit with nuclear spins. We show that the Hahn-echo coherence time is determined by a complex interplay between the source of decoherence in the qubit host and in the environment, which in turn determines whether the noise evolution is in a classical or quantum mechanical regime. We suggest that the composition and thickness of van-der-Waals heterostructures encapsulating a qubit host can be engineered to maximize coherence times. Finally, we discuss how quantum sensors may be able to probe the dynamics of the nuclear bath in 2DMs.