Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Compensation of decoherence from telegraph noise by means of bang-bang
  control   With the growing efforts in isolating solid-state qubits from external
decoherence sources, the origins of noise inherent to the material start to
play a relevant role. One representative example are charged impurities in the
device material or substrate, which typically produce telegraph noise and can
hence be modelled as bistable fluctuators. In order to demonstrate the
possibility of the active suppression of the disturbance from a {\em single}
fluctuator, we theoretically implement an elementary bang-bang control
protocol. We numerically simulate the random walk of the qubit state on the
Bloch sphere with and without bang-bang compensation by means of the stochastic
Schr\"odinger equation and compare it with an analytical saddle point solution
of the corresponding Langevin equation in the long-time limit. We find that the
deviation with respect to the noiseless case is significantly reduced when
bang-bang pulses are applied, being scaled down approximately by the ratio of
the bang-bang period and the typical flipping time of the bistable fluctuation.
Our analysis gives not only the effect of bang-bang control on the variance of
these deviations, but also their entire distribution. As a result, we expect
that bang-bang control works as a high-pass filter on the spectrum of noise
sources. This indicates how the influence of $1/f$-noise ubiquitous to the
solid state world can be reduced.

18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
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The categories of this paper are: chem-ph
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph