Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum non-demolition measurements of single donor spins in
  semiconductors   We propose a technique for measuring the state of a single donor electron
spin using a field-effect transistor induced two-dimensional electron gas and
electrically detected magnetic resonance techniques. The scheme is facilitated
by hyperfine coupling to the donor nucleus. We analyze the potential
sensitivity and outline experimental requirements. Our measurement provides a
single-shot, projective, and quantum non-demolition measurement of an
electron-encoded qubit state.

14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph