52 research outputs found
Signatures of fractionalization in spin liquids from interlayer thermal transport
Quantum spin liquids (QSLs) are intriguing phases of matter possessing
fractionalized excitations. Several quasi-two dimensional materials have been
proposed as candidate QSLs, but direct evidence for fractionalization in these
systems is still lacking. In this paper, we show that the inter-plane thermal
conductivity in layered QSLs carries a unique signature of fractionalization.
We examine several types of gapless QSL phases - a QSL with either a
Dirac spectrum or a spinon Fermi surface, and a QSL with a Fermi
surface. In all cases, the in-plane and axis thermal conductivities have a
different power law dependence on temperature, due to the different mechanisms
of transport in the two directions: in the planes, the thermal current is
carried by fractionalized excitations, whereas the inter-plane current is
carried by integer (non-fractional) excitations. In layered and
QSLs with a Fermi surface, the axis thermal conductivity is parametrically
smaller than the in-plane one, but parametrically larger than the phonon
contribution at low temperatures
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