Events

Next Quantum Material Seminar/LANEF:

Tuesday, May 16th 2023 at 11:00 am

Anne De Visser (Van der Waals-Zeeman Institute, University of Amsterdam)

“ Type-I superconductivity in the Dirac semimetal PdTe₂”

To access this seminar:

Institut Néel CNRS, Building K, Room Rémy Lemaire  (K223)

Abstract: The family of transition metal dichalcogenides attracts ample attention, because of the ubiquitous presence of topological features in the electronic band structure. Here the focus is on PdTe₂ that was classified as a Type-II Dirac semimetal [1], and becomes superconducting below T_c = 1.6 K [2]. This prompts the question whether superconductivity has a topological nature. In this presentation I report an in-depth characterization of the superconducting properties of PdTe₂ by means of electrical resistivity, magnetization, susceptibility and heat capacity measurements carried out on single crystalline samples [3]. Surprisingly, we find that PdTe₂ is a Type-I superconductor, which is rare for a binary compound. Type-I behaviour is furthermore confirmed by the detection of the intermediate state in mSR [4] and scanning SQUID measurements [5]. Interestingly, we also find an unusual type of surface superconductivity corroborated by the ac-susceptibility screening signal [3], which is robust under high pressure [6]. The unusual field-temperature phase diagram, with bulk and surface superconductivity, will be discussed in view of the topological electronic structure of PdTe₂.

References

[1] M.S. Bahramy et al., Nat. Mater. 17, 21 (2018).
[2] J. Guggenheim et al., Helv. Phys. Acta 34, 408 (1961).
[3] H. Leng et al., Phys. Rev. B 96, 220506R (2017).
[4] H. Leng et al., Phys. Rev. B 100, 224501 (2019).
[5] P. Garcia-Campos et al., Phys. Rev. B 103, 104510 (2021).
[6] H. Leng et al., J. Phys. Cond. Mat. 32, 025603 (2020).

The organizers:

Elsa Lhotel (elsa.lhotel@neel.cnrs.fr)
Florence Levy-Bertrand (florence.levy-bertrand@neel.cnrs.fr)