Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Generating Entanglement and Squeezed States of Nuclear Spins in Quantum
  Dots   Entanglement generation and detection are two of the most sought-after goals
in the field of quantum control. Besides offering a means to probe some of the
most peculiar and fundamental aspects of quantum mechanics, entanglement in
many-body systems can be used as a tool to reduce fluctuations below the
standard quantum limit. For spins, or spin-like systems, such a reduction of
fluctuations can be realized with so-called squeezed states. Here we present a
scheme for achieving coherent spin squeezing of nuclear spin states in
few-electron quantum dots. This work represents a major shift from earlier
studies in quantum dots, which have explored classical "narrowing" of the
nuclear polarization distribution through feedback involving stochastic spin
flips. In contrast, we use the nuclear-polarization-dependence of the electron
spin resonance (ESR) to provide a non-linearity which generates a non-trivial,
area-preserving, "twisting" dynamics that squeezes and stretches the nuclear
spin Wigner distribution without the need for nuclear spin flips.

23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph