Thermopower and thermoelectric power factor of Zk{\mathbb Z}_k parafermion quantum dots

Using the conformal field theory approach to the thermoelectric characteristics of fractional quantum Hall states, previously developed in Nucl. Phys. B 894 (2015) 284, we show that the thermoelectric power factor of Coulomb-blockaded islands, realized by point contacts in Fabry--P\'erot interferometers in the $\mathbb{Z}_k$ parafermion Hall states, could give reliable signatures for distinguishing the topological orders of different quantum Hall states having identical electric properties. For example, while the conductance peak patterns in the Coulomb blockade regime for such states are practically indistinguishable for $v_n \ll v_c$ even at finite temperature, where $v_n$ and $v_c$ are the Fermi velocities of the neutral and charged modes respectively, the power factors $\mathcal{P}_T$ of the corresponding states are much more sensitive to the neutral modes. In particular, the smaller $r=v_n/v_c$ the bigger the asymmetries in the power factor which combined with the thermal broadening of the conductance peaks due to the neutral modes' multiplicities could give us the ultimate tool to figure out which of the competing quantum Hall universality classes are indeed realized in the experiments. We give a complete description of the power factor profiles in the $\mathbb{Z}_3$ and $\mathbb{Z}_4$ parafermion states with arbitrary number of quasiparticles localized in the bulk which could be useful for comparison with the experiments.Comment: 27 pages, 12 PDF figures; v2: added two more references and corrected several misprint

Thermoelectric properties of Coulomb-blockaded fractional quantum Hall islands

We show that it is possible and rather efficient to compute at non-zero temperature the thermoelectric characteristics of Coulomb blockaded fractional quantum Hall islands, formed by two quantum point contacts inside of a Fabry-Perot interferometer, using the conformal field theory partition functions for the chiral edge excitations. The oscillations of the thermopower with the variation of the gate voltage as well as the corresponding figure-of-merit and power factors, provide finer spectroscopic tools which are sensitive to the neutral multiplicities in the partition functions and could be used to distinguish experimentally between different universality classes. We also propose a procedure for measuring the ratio r=v_n/v_c of the Fermi velocities of the neutral and charged edge modes for filling factor \nu=5/2 from the power-factor data in the low-temperature limit.Comment: 27 pages, 12 figure