Large spatial Schrödinger cat state using a levitated ferrimagnetic nanoparticle

Abstract

The superposition principle is one of the main tenets of quantum mechanics. Despite its counterintuitiveness, 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 nonmagnetic silica shell, can be used to probe quantum gravity.

Quantum experiments with microscale particles

“…In contrast to microscopic quantum systems, nanoscale dielectrics lack such discrete internal levels that could be coherently addressed by laser pulses. However, nanoparticles can be artificially endowed with few-level systems by embedding single NV centres [84][85][86][87][88] or by entangling them with superconducting [25,37,38,89] or ion [90,91] qubits.…”

“…For nanodiamonds with embedded NV spins, this scheme can be enacted by exploiting the spin-dependent force in an inhomogeneous magnetic field [84][85][86][87][88]. In a similar fashion, dielectric nanoparticles can be entangled with co-trapped ion qubits through a high finesse optical cavity mode [90], highly charged nanoparticles in ion traps can be conditionally displaced by an electric field determined by the state of a superconducting charge qubit [25], and magnetic particles can be inductively coupled to flux qubits [37,38,89].…”

Optomagnonically induced RoF chaotic synchronization

“…The YIG resonator can be a various structures such as planar [7], cylindrical [12], and ellipsoidal [17,18]. Various phenomena and applications such as frequency combs [19,20], chaos [21][22][23][24], photon blockade [25], ground-state cooling [26], quantum state squeezing [27], cat state control [17,[28][29][30], and microwave-optical transducers [7,31], and others [32][33][34][35][36][37] have been reported.…”

Remote generation of magnon Schrödinger cat state via magnon-photon entanglement

“…This approach has been recently investigated for the preparation of a magnon cat state in an ideal system without decoherence [34]. As the coupling to environment is inevitable in all practical situations, it is crucial to explore efficient ways to create magnon cat states in realistic conditions [35] and evaluate their nonclassical qualities by taking damping processes into account.…”