Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Local Geometric Phase and Quantum State Tomography in a Superconducting
  Qubit   We investigate quantum state reconstruction of a superconducting qubit
threaded by an Aharonov-Bohm flux, with particular attention to the local
geometric phase. A state reconstruction scheme is introduced with a proper
account of the local geometric phase generated by Faraday's law of induction.
Our scheme is based on measurement of three complementary quantities, that is,
the extra charge and two local currents. Incorporating time-reversal symmetry
and the Faraday's law, we show that the full density matrix can be
reconstructed without ambiguity in the choice of gauge. This procedure clearly
demonstrates that the quantum Faraday effect plays an essential role in the
dynamics of a quantum system that involves Aharonov-Bohm flux.

31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess