Warning: Use of undefined constant view - assumed 'view' (this will throw an Error in a future version of PHP) in /var/www/www/templates/intibs2020/index.php on line 92


Department of Magnetic Reseach Seminar

13:30, 19-01-30
sala nr 6 (bud. II)

Dirac states in Pd-Bi superconductors: on the hunt for Majorana modes

prof. Dr hab. Dariusz Kaczorowski

Topological superconductor (TSC) hosting Majorana fermions has been established as a milestone that might shift our scientific trajectory from fundamental research to practical applications in topological quantum computing. Recently, superconducting Pd-Bi binaries, due to their inherently large spin-orbit coupling strength, have attracted much attention as a possible platform for realization of the TSC phase.

Here, we present the electrical transport and thermodynamic properties of two such binaries, namely α-PdBi2 (Tc = 1.7 K), crystallizing with a monoclinic centrosymmetric unit cell (space group C2/m) [1], and PdBi (Tc = 3.7 K), forming with a monoclinic noncentrosymmetric crystal structure (space group P1211) [2]. Then, we discuss the results of our comprehensive studies on the electronic structures of these compounds by means of high-resolution angle- and spin-resolved photoemission spectroscopy (ARPES) and ab-initio band structure calculations [1,2].

In each material we observed Dirac states at high binding energy with a Dirac node located at about 0.7 and 1.26 eV below the chemical potential for mono- and dibismuthide, respectively. In the case of PdBi, the absence of spin-polarized surface states near the Fermi level negates the possibility that this system might host topological superconductivity on the surface. In turn, for α-PdBi2, multiple surface Rashba states were found in the vicinity of the chemical potential, which might be utilized to realize Majorana fermions [4].

This research was supported by the National Science Centre (Poland) under grant no. 2015/18/A/ST3/00057.

[1] K. Dimitri, et al., Phys. Rev. B 97, 144514 (2018).
[2] M. Neupane, et al., Nat. Comm. 7, 13315 (2016).
[3] A. C. Potter and P. A. Lee, Phys. Rev. B 85, 094516 (2012).

im. Włodzimierza Trzebiatowskiego
Institute address:
ul. Okólna 2, 50-422 Wrocław
Electronic address::
71 343 5021, 71 395 4xxx
Fax: 71 344 1029
Mon - Fri 7:30-15:30