Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Experimental identification of quantum spin liquids   In condensed matter physics, there is a novel phase termed "quantum spin
liquid", in which strong quantum fluctuations prevent the long-range magnetic
order from being established, and so the electron spins do not form an ordered
pattern but remain "liquid" like even at absolute zero temperature. Such a
phase is not involved with any spontaneous symmetry breaking and local order
parameter, and to understand it is beyond the conventional phase transition
theory. Due to the rich physics and exotic properties of quantum spin liquids,
such as the long-range entanglement and fractional quantum excitations, which
are believed to hold great potentials in quantum communication and computation,
they have been intensively studied since the concept was proposed in 1973 by P.
W. Anderson. Currently, experimental identifications of a quantum spin liquid
still remain as a great challenge. Here, we highlight some interesting
experimental progress that has been made recently. We also discuss some
outstanding issues and raise questions that we consider to be important for
future research.

15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex