Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detecting entanglement using a double quantum dot turnstile   We propose a scheme based on using the singlet ground state of an electron
spin pair in a double quantum dot nanostructure as a suitable set-up for
detecting entanglement between electron spins via the measurement of an optimal
entanglement witness. Using time-dependent gate voltages and magnetic fields
the entangled spins are separated and coherently rotated in the quantum dots
and subsequently detected at spin-polarized quantum point contacts. We analyze
the coherent time evolution of the entangled pair and show that by counting
coincidences in the four exits an entanglement test can be done. This set-up is
close to present-day experimental possibilities and can be used to produce
pairs of entangled electrons ``on demand''.

31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th