Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum-disordered state of magnetic and electric dipoles in a
  hydrogen-bonded Mott system   Strongly enhanced quantum fluctuations often lead to a rich variety of
quantum-disordered states. A representative case is liquid helium, in which
zero-point vibrations of the helium atoms prevent its solidification at low
temperatures. A similar behaviour is found for the internal degrees of freedom
in electrons. Among the most prominent is a quantum spin liquid (QSL), in which
localized spins are highly correlated but fluctuate even at absolute zero.
Recently, a coupling of spins with other degrees of freedom has been proposed
as an innovative approach to generate even more fascinating QSLs such as
orbital--spin liquids. However, such ideas are limited to the internal degrees
of freedom in electrons. Here, we demonstrate that a coupling of localized
spins with the zero-point motion of hydrogen atoms (proton fluctuations) in a
hydrogen-bonded organic Mott insulator provides a new class of QSLs. We find
that a divergent dielectric behaviour towards a hydrogen-bond order is
suppressed by the quantum proton fluctuations, resulting in a quantum
paraelectric (QPE) state. Furthermore, our thermal-transport measurements
reveal that a QSL state with gapless spin excitations rapidly emerges upon
entering the QPE state. These findings indicate that the quantum proton
fluctuations give rise to a novel QSL --- a quantum-disordered state of
magnetic and electric dipoles --- through the coupling between the electron and
proton degrees of freedom.

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The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
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The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics