Bose\u2013Einstein condensate soliton qubit states for metrological applications

The Vinh Ngo,Alexander P Alodjants,Dmitriy V Tsarev,Ray-Kuang Lee

doi:10.1038/s41598-021-97971-4

The Vinh Ngo, Alexander P Alodjants + Show 2 more

Open Access

https://doi.org/10.1038/s41598-021-97971-4

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Journal: Scientific Reports	Publication Date: Sep 29, 2021
Citations: 3	License type: open-access

Affiliation: ITMO University, National Tsing Hua University

Abstract

We propose a novel platform for quantum metrology based on qubit states of two Bose–Einstein condensate solitons, optically manipulated, trapped in a double-well potential, and coupled through nonlinear Josephson effect. We describe steady-state solutions in different scenarios and perform a phase space analysis in the terms of population imbalance—phase difference variables to demonstrate macroscopic quantum self-trapping regimes. Schrödinger-cat states, maximally path-entangled (N00N) states, and macroscopic soliton qubits are predicted and exploited to distinguish the obtained macroscopic states in the framework of binary (non-orthogonal) state discrimination problem. For an arbitrary frequency estimation we have revealed these macroscopic soliton states have a scaling up to the Heisenberg and super-Heisenberg (SH) limits within linear and nonlinear metrology procedures, respectively. The examples and numerical evaluations illustrate experimental feasibility of estimation with SH accuracy of angular frequency between the ground and first excited macroscopic states of the condensate in the presence of moderate losses, which opens new perspectives for current frequency standard technologies.

Highlights

We propose a novel platform for quantum metrology based on qubit states of two Bose–Einstein condensate solitons, optically manipulated, trapped in a double-well potential, and coupled through nonlinear Josephson effect
Atomic optics, which operates with Bose–Einstein condensates (BECs) at low temperatures, provides a suitable platform for various quantum devices that may be useful for metrology and sensing tasks[9]
We have considered the problem of two-soliton formation for 1D BECs trapped effectively in a double-well potential

Summary

Introduction

We propose a novel platform for quantum metrology based on qubit states of two Bose–Einstein condensate solitons, optically manipulated, trapped in a double-well potential, and coupled through nonlinear Josephson effect. The bifurcation effect and MQST states, which are the features of the coupled solitons (Fig. 1) at the zero-phase regime, do not occur for the condensates described by Gaussian states[28,29]. As we show below, may be exploited for the macroscopic superposition soliton states formation in the quantum approach.

Results

Conclusion