Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Supersensitive measurement using single-atom control of an atomic
  ensemble   We analyze the operation of a novel sensor based on atom interferometry,
which can achieve supra-classical sensitivity by exploiting quantum
correlations in mixed states of many qubits. The interferometer is based on
quantum gates which use coherently-controlled Rydberg interactions between a
single atom (which acts as a control qubit) and an atomic ensemble (which
provides register qubits). In principle, our scheme can achieve precision
scaling with the size of the ensemble - which can extend to large numbers of
atoms - while using only single-qubit operations on the control and bulk
operations on the ensemble. We investigate realistic implementation of the
interferometer, and our main aim is to develop a new approach to quantum
metrology that can achieve quantum-enhanced measurement precision by exploiting
coherent operations on large impure quantum states. We propose an experiment to
demonstrate the enhanced sensitivity of the protocol, and to investigate a
transition from classical to supra-classical sensitivity which occurs when
using highly-mixed probe states.

20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn