Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: p-Type doping of II-VI heterostructures from surface states: application
  to ferromagnetic Cd$_{1-x}$Mn$_x$Te quantum wells   We present a study of p-type doping of CdTe and Cd$_{1-x}$Mn$_x$Te quantum
wells from surface states. We show that this method is as efficient as usual
modulation doping with nitrogen acceptors, and leads to hole densities
exceeding $2 \times 10^{11}$ cm$^{-2}$. Surface doping was successfully applied
to obtain carrier-induced ferromagnetism in a Cd$_{1-x}$Mn$_x$Te quantum well.
The observed temperature dependence of photoluminescence spectra, and the
critical temperature, correspond well to those previously reported for
ferromagnetic quantum wells doped with nitrogen.

19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph