Gapless excitations in the ground state of 1T-TaS2

MPSD Seminar

  • Datum: 07.06.2018
  • Uhrzeit: 09:30 - 10:30
  • Vortragende(r): Amit Ribak
  • ARPES Group, Department of Physics, Technion - Israel Institute of Technology
  • Ort: CFEL (Bldg. 99)
  • Raum: Seminar Room V, O1.109
  • Gastgeber: Andrea Cavalleri
1T-TaS2 is a layered transition metal dichalcogenide with a very rich phase diagram, which was investigated since the early 1970s. At T=180K it undergoes a metal to Mott insulator transition. Mott insulators usually display anti-ferromagnetic ordering in the insulating phase but 1T-TaS2 was never shown to order magnetically. We have shown that 1T-TaS2 has a large paramagnetic contribution to the magnetic susceptibility but it does not show any sign of magnetic ordering or freezing down to 20mK, as probed by muSR, possibly indicating a quantum spin liquid ground state. Although 1T-TaS2 exhibits a strong resistive behavior both in and out of plane at low temperatures we find a linear term in the heat capacity suggesting the existence of a Fermi-surface, which has an anomalously strong magnetic field dependence.
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