Correlations and topology in a hybrid compound

Seminar
QUEST Center event
No
Speaker
Haim Beidenkopf, Weizmann Institute
Date
25/04/2022 - 15:00 - 13:30Add to Calendar 2022-04-25 13:30:00 2022-04-25 15:00:00 Correlations and topology in a hybrid compound Zoom link: https://us02web.zoom.us/j/89236785442 Haim Beidenkopf, Weizmann Institute Abstract A small change in the crystal structure of a material can completely modify its electronic properties. This is the case in the transition metal dichalcogenide TaS2 where a slight rotation of the sulphur atoms from the trigonal prismatic 1H structure to the octahedral 1T varies it from a superconductor to a Mott insulator possibly hosting a spin liquid state. We have studied 4Hb-TaS2 that interleaves the 1T and 1H polytypes. This has allowed us to investigate using scanning tunneling spectroscopy the fate of a Mott insulator when coupled to a metal and the superconducting phase that results from sandwiching it with Mott insulating layers. In the former we find a quantum phase transition that can be induced by the STM tip, electric field and temperature which possibly signifies the onset of correlations among Anderson impurities (or of a Kondo lattice). In the latter we identify a topological nodal superconducting state which we attribute to interaction-promoted inter-orbital pairing. Physics Building 202, Room 301 and https://us02web.zoom.us/j/89236785442 Department of Physics physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
Physics Building 202, Room 301 and https://us02web.zoom.us/j/89236785442
Abstract

Zoom link: https://us02web.zoom.us/j/89236785442

Haim Beidenkopf, Weizmann Institute

Abstract

A small change in the crystal structure of a material can completely modify its electronic properties. This is the case in the transition metal dichalcogenide TaS2 where a slight rotation of the sulphur atoms from the trigonal prismatic 1H structure to the octahedral 1T varies it from a superconductor to a Mott insulator possibly hosting a spin liquid state. We have studied 4Hb-TaS2 that interleaves the 1T and 1H polytypes. This has allowed us to investigate using scanning tunneling spectroscopy the fate of a Mott insulator when coupled to a metal and the superconducting phase that results from sandwiching it with Mott insulating layers. In the former we find a quantum phase transition that can be induced by the STM tip, electric field and temperature which possibly signifies the onset of correlations among Anderson impurities (or of a Kondo lattice). In the latter we identify a topological nodal superconducting state which we attribute to interaction-promoted inter-orbital pairing.

Last Updated Date : 24/04/2022