Large spatial Schrödinger cat state using a levitated ferrimagnetic nanoparticle

A T M Anishur Rahman

doi:10.1088/1367-2630/ab4fb3

Abstract

The superposition principle is one of the main tenets of quantum mechanics. Despite its counter-intuitiveness, it has been experimentally verified using electrons, photons, atoms, and molecules. However, a similar experimental demonstration using a nano or a micro particle is non-existent. Here in this article, exploiting macroscopic quantum coherence and quantum tunneling, we propose an experiment using a levitated magnetic nanoparticle to demonstrate such an effect. It is shown that the spatial separation between the delocalized wavepackets of a 20 nm ferrimagnetic yttrium iron garnet (YIG) nanoparticle can be as large as 5 μm. We argue that, in addition to using for testing one of the most fundamental aspects of quantum mechanics, this scheme can simultaneously be used to test different modifications, such as wavefunction collapse models, to the standard quantum mechanics. Furthermore, we show that the spatial superposition of a core–shell structure, a YIG core and a non-magnetic silica shell, can be used to probe quantum gravity.

Highlights

Quantum mechanics permits an object, big, to be spatially delocalized in two different places at once [1, 2, 3, 4]
The large spatial separation (5 μm) between the delocalized matter-wave packets that the current scheme can produce is ideal for testing wave-function collapse models such as the continuous spontaneous localization (CSL) [15]
In this article we have theoretically shown that exploiting the naturally occurring spin superposition in a yttrium iron garnet nanoparticle and an appropriate magnetic field gradient, a large Schrodinger cat can be created

Summary

Introduction

Quantum mechanics permits an object, big, to be spatially delocalized in two different places at once [1, 2, 3, 4]. Apart from being of pure fundamental interest, a macroscopic superposition state is of significant practical relevance due to the emergence of quantum technologies e.g. quantum computing and communications [18]. That is the superposition principle is the essential ingredient of quantum computing [18] as well as behind the absolute security of quantum communications [19]. Understanding the superposition principle at the macroscopic level can enrich our knowledge about the nature around us and can improve metrology, and quantum computing and communications [13]

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Discussion

Conclusion