Superconductivity in 4Hb TaS2 Chiral or Nematic?

by Prof. Yoram Dagan

at Condensed Matter Seminar

Mon, 20 Jun 2022, 11:30
Sacta-Rashi Building for Physics (54), room 207


TaS2 in its 4Hb polytype comprises alternatingly stacked layers of 1H and 1T. Its superconducting state appears at an order of magnitude higher temperature than the 1H TaS2. Signatures of time-reversal symmetry breaking appearing at the superconducting transition temperature have recently been reported [1].
We perform transport and heat capacity measurements at high magnetic fields. Our transport results suggest that the superconducting state has a two-fold symmetry, with the weakest superconducting state formed along a particular crystal axis. In addition, the critical field has an anomalous temperature dependence. By contrast, specific heat measurements suggest that the amplitude of the order parameter is roughly constant around the Fermi contour. Scanning tunneling microscopy observes a stripe-like structure manifested as a weak periodic modulation of the density of states. I will discuss various scenarios to explain our data.
[1] A. Ribak, R. M. Skif, M. Mograbi, P. K. Rout, M. H. Fischer, J. Ruhman, K. Chashka, Y. Dagan, and A. Kanigel, Sci. Adv. 6, 9480 (2020).

Created on 18-06-2022 by Meidan, Dganit (dganit)
Updaded on 18-06-2022 by Meidan, Dganit (dganit)