Enhanced superconductivity originating from f -electron doping in topologically nontrivial YPdBi half-Heusler thin films
Journal article, 2024

YPdBi is a well-studied diamagnetic topologically trivial half-Heusler alloy that is superconducting with Tc∼1 K. When strained or in thin-film form, it shows a topologically nontrivial surface state with Tc ∼1.25K. ErPdBi is a well-studied topologically nontrivial half Heusler with Tc ∼1.22K. In this work, we demonstrate that the f-electron doping in YPdBi provides a unique way to selectively tune the electronic structure and aid in increasing the superconducting transition temperature of YPdBi. This work presents systematic measurements of electrical resistivity and magnetotransport on half-Heusler thin films of Y(1-x)ErxPdBi (x=0.2, 0.5, and 0.8), prepared using the pulsed laser deposition technique. All the films were observed to be semimetallic, with a sharp downturn in resistivity at low temperatures T < 5 K; the E5 film (Tc∼4.4 K) and E8 film (Tc∼3.7 K) reach a zero-resistivity value, within the experimental limit. The doping of f electron on Y+3 sites possibly gives rise to the improved Fermi parameters and an increase in Tc. Magnetoresistance measurements and first-principle calculations support that Y(1-x)ErxPdBi are topologically nontrivial semimetals. The first-principle calculations also show that with an increase in the doping concentration (x), more f bands start to appear near Fermi level (EF), giving rise to an increase in the band-inversion strength due to s-f exchange interaction. The nontrivial band structure, odd-parity Cooper pair, and noncentrosymmetric crystal structure suggest the presence of unconventional superconductivity in the E5 and E8 films.

Author

Shivangi Srivastava

Indian Institute of Technology

Bishal Das

Indian Institute of Technology

Vishal Bhardwaj

Weizmann Institute of Science

Aftab Alam

Indian Institute of Technology

Saroj Prasad Dash

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Ratnamala Chatterjee

National University of Science & Technology (MISIS)

Indian Institute of Technology

Physical Review Materials

24759953 (eISSN)

Vol. 8 7 075001

Subject Categories

Condensed Matter Physics

DOI

10.1103/PhysRevMaterials.8.075001

More information

Latest update

7/30/2024