2014/03/31 by Kridsanaphong Limtragool, Philip Phillips, Philip W. Phillips · 1 citation
Mathematics · Physics and Astronomy · #Condensed matter physics #Counterexample #Electron #Gauge theory #Hamiltonian (control theory) #Mathematics #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Quantum phase transition #Seebeck coefficient #Strongly correlated material #Thermoelectric effect #Topological Materials and Phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.113.086405
published in Physical Review Letters 113(8), 086405 (American Physical Society) · 4.5 pages, 5 figures. An internal footnote is added regarding how the thermopower can be uniquely defined for the models treated here
arxiv created 2014/04/29 · openalex publication_date 2014/08/22 · arxiv updated 2014/08/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
A general principle of modern statistical physics is that divergences of either thermodynamic or transport properties are only possible if the correlation length diverges. We show by explicit calculation that the thermopower in the quantum XY model d = 1 + 1 and the Kitaev model in d = 2 + 1 can (i) diverge even when the correlation length is finite and (ii) remain finite even when the correlation length diverges, thereby providing a counterexample to the standard paradigm. Two conditions are necessary: (i) the sign of the charge carriers and that of the group velocity must be uncorrelated and (ii) the current operator defined formally as the derivative of the Hamiltonian with respect to the gauge field does not describe a set of excitations that have a particle interpretation, as in strongly correlated electron matter. Recent experimental and theoretical findings on the divergent thermopower of a 2D electron gas are discussed in this context.