SciPost Submission Page
Topological thermal Hall effect for topological excitations in spin liquid: Emergent Lorentz force on the spinons
by Yong Hao Gao, Gang Chen
|As Contributors:||Gang Chen|
|Submitted by:||Chen, Gang|
|Submitted to:||SciPost Physics|
|Subject area:||Condensed Matter Physics - Theory|
We study the origin of Lorentz force on the spinons in a U(1) spin liquid. We are inspired by the previous observation of gauge field correlation in the pairwise spin correlation using the neutron scattering measurement when the Dzyaloshinskii-Moriya interaction intertwines with the lattice geometry. We extend this observation to the Lorentz force that exerts on the (neutral) spinons. The external magnetic field, that polarizes the spins, effectively generates an internal U(1) gauge flux for the spinons and twists the spinon motion through the Dzyaloshinskii-Moriya interaction. Such a mechanism for the emergent Lorentz force differs fundamentally from the induction of the internal U(1) gauge flux in the weak Mott insulating regime from the charge fluctuations. We apply this understanding to the specific case of spinon metals on the kagome lattice. Our suggestion of emergent Lorentz force generation and the resulting topological thermal Hall effect may apply broadly to other non-centrosymmetric spin liquids with Dzyaloshinskii-Moriya interaction. We discuss the relevance with the thermal Hall transport in kagome materials volborthite and kapellasite.
Submission & Refereeing History
Reports on this Submission
Anonymous Report 1 on 2019-8-1 Invited Report
1. Very readable paper, nicely written on the whole.
2. Makes a contribution to the literature.
3. No technical faults
1. Major weakness is whether the work is of high enough significance to warrant publication in scipost
2. Use of the word "Topological" for this thermal hall effect (despite other papers doing similarthings) seems deceptive and should be avoided.
3. Citation should be added into abstract.
Overall I liked this paper -- it is clear and well written. My concern, however, is that it is not a sufficient advance to warrant publication in SciPost (which requires a somewhat higher level of work than, for example, PRB, in my understanding). The problem is that the results seems hardly surprising. (a) it is hardly surprising (based on symmetry) that once you add a zeeman field you will generate a chiral order parameter (b) once you have a nonzero chiral order parameter it is hardly surprising that you will have a thermal hall effect roughly proportional linear in the order parameter at least for small values. If either (a) or (b) is surprising, it is not clear to me why, and it is not explained in the manuscript. If the authors can explain this convincingly I would be happy to recommend it for publication. Otherwise, I'm not sure it is interesting enough. So although I will label the paper as "minor revision", unless the authors convince me it is interesting enough, I'm hesitant to recommend publication.
I have two further comments. First, I don't think using the word "topological" is really acceptable here. What is topological in this calculation? You use berry curvature, but this is not topological -- it is a geometric curvature, and unless you integrate over the whole zone to get a chern band, which you don't, it is not topological. There are no topological invariants, and no topological objects. The word topological is simply out of place and it seems like people just insert the word "topological" randomly in order to attract attention. I know the word has been used similarly in other publications, but this does not make it correct.
My final point is very minor. The abstract states that this work is based on prior work (second and third sentences of the abstract). These works should be cited within the abstract to clarify. With abstract citation, the entire publication information should be within the abstract itself. The way it stands it is quite hard for the reader to figure out what reference the authors mean until half-way through the paper.
1. Clarify why this is important/interesting enough to be in SciPost
2. Remove use of word "topological" where it is not appropriate (including the title)
3. Include appropriate citation in abstract.