Spin-Controlled Quantum Interference of Levitated Nanorotors

TL;DR

This paper proposes a method to control and observe quantum superpositions of a levitated nanodiamond's orientation using microwave driving of an embedded NV center, advancing quantum control of macroscopic objects.

Contribution

It introduces a protocol for preparing and detecting quantum superpositions of nanodiamond orientations via spin-rotation coupling and derives the effective Hamiltonian for small rotations.

Findings

The protocol enables creating superpositions of particle orientations.

The effective Hamiltonian describes spin-rotation interactions in the ultrastrong coupling regime.

Decoherence effects are analyzed, indicating feasible experimental implementation.

Abstract

We describe how to prepare an electrically levitated nanodiamond in a superposition of orientations via microwave driving of a single embedded nitrogen-vacancy (NV) center. Suitably aligning the magnetic field with the NV center can serve to reach the regime of ultrastrong coupling between the NV and the diamond rotation, enabling single-spin control of the particle's three-dimensional orientation. We derive the effective spin-oscillator Hamiltonian for small amplitude rotation about the equilibrium configuration and develop a protocol to create and observe quantum superpositions of the particle orientation. We discuss the impact of decoherence and argue that our proposal can be realistically implemented with near-future technology.