Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Force sensors with precision beyond the standard quantum limit   We propose force sensing protocols using linear ion chain which can operate
beyond the quantum standard limit. We show that oscillating forces that are
off-resonance with the motional trap frequency can be detected very efficiently
by using quantum probes represented by various spin-boson models. We
demonstrate that the temporal evolution of a quantum probe described by the
Dicke model can be mapped on the nonlinear Ramsey interferometry which allows
to detect far-detuned forces simply by measuring the collective spin
populations. Moreover, we show that the measurement uncertainty can reach the
Heisenberg limit by using initial spin correlated states, instead of motional
entangled states. An important advantage of the sensing technique is its
natural robustness against the thermally induced dephasing, which extends the
coherence time of the measurement protocol. Furthermore, we introduce sensing
scheme that utilize the strong spin-phonon coupling to improve the force
estimation. We show that for quantum probe represented by quantum Rabi model
the force sensitivity can overcome those using simple harmonic oscillator as a
force sensor.

4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin