Many-body quantum metrology with scalar bosons in a single potential well

TL;DR

This paper explores how intrinsic interactions in a single-well bosonic system can enhance quantum metrology precision, specifically for acceleration estimation, by analyzing the quantum Fisher information for different initial states.

Contribution

It introduces a theoretical model showing that interactions in a single-well bosonic system can significantly improve quantum metrology precision, differing from traditional double-well approaches.

Findings

Interactions increase quantum Fisher information for various initial states.

Intrinsic dynamics can enhance measurement precision without external splitting.

Single-well bosonic systems can achieve high-precision estimation through many-body effects.

Abstract

We theoretically investigate the possibility of performing high precision estimation of an externally imposed acceleration using scalar bosons in a single-well trap. We work at the level of a two-mode truncation, valid for weak to intermediate two-body interaction couplings.The splitting process into two modes is in our model entirely caused by the interaction between the constituent bosons and is hence neither due to an externally imposed double-well potential nor due to populating a spinor degree of freedom. The precision enhancement gained by using various initial quantum states using a two-mode bosonic system is well established. Here we therefore instead focus on the effect of the intrinsic dynamics on the precision, where, in a single well, the Hamiltonian assumes a form different from that of the typical double-well case. We demonstrate how interactions can significantly increase the quantum Fisher information maximized over initial states as well as the quantum Fisher information for a fragmented or a coherent state, the two many-body states that can commonly represent the ground state of our system.