Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Closing the Pseudogap by Zeeman Splitting in Bi_2Sr_2CaCu_2O_8+y at High
  Magnetic Fields   Interlayer tunneling resistivity is used to probe the low-energy
density-of-states (DOS) depletion due to the pseudogap in the normal state of
Bi$_2$Sr$_2$CaCu$_2$O$_{8+y}$. Measurements up to 60 T reveal that a field that
restores DOS to its ungapped state shows strikingly different temperature and
doping dependencies from the characteristic fields of the superconducting
state. The pseudogap closing field and the pseudogap temperature $T^{\star}$
evaluated independently are related through a simple Zeeman energy scaling.
These findings indicate a predominant role of spins over the orbital effects in
the formation of the pseudogap.

1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom