Gauge theories for the thermal Hall effect

Article

关键词: NONZERO-TEMPERATURE TRANSPORT;    FIELD;    FLUCTUATION;    FLUX;   

DOI  :  10.1103/PhysRevB.101.195126

来源: SCIE

【 摘 要 】

We consider the thermal Hall effect of fermionic matter coupled to emergent gauge fields in 2 + 1 dimensions. While the low-temperature thermal Hall conductivity of bulk topological phases can be connected to chiral edge states and a gravitational anomaly, there is no such interpretation at nonzero temperatures above 2 + 1-dimensional quantum critical points. In the limit of a large number of matter flavors, the leading contribution to the thermal Hall conductivity is that of the fermionic matter. The next-to-leading contribution is from the gauge fluctuations, and this has a sign which is opposite to that of the matter contribution. We illustrate this by computations on a Dirac Chern-Simons theory of the quantum phase transition in a square-lattice antiferromagnet involving the onset of semion topological order. We find similar results for a model of the pseudogap metal with Fermi pockets coupled to an emergent U(1) gauge field. We note connections to recent observations on the hole-doped cuprates: our theory captures the main trends, but the overall magnitude of the effect is smaller than that observed.

【 授权许可】

Free