Wydarzenia

Seminarium Instytutu Niskich Temperatur i Badań Strukturalnych PAN

Superconductivity in materials without inversion symmetry: simple vs. correlated systems

prof. dr Ernst Bauer

Vienna University of Technology, Austria

Seminarium z cyklu: "Aktualne Problemy Fizyki Fazy Skondensowanej"

Superconductors missing a centre of symmetry in the crystal structure are subject to peculiar band splitting, which is detrimental to certain kinds of Cooper pairing channels. In particular, spin triplet pairing was claimed to become unlikely under such circumstances. Ternary CePt₃Si is the first representative of heavy fermion superconductors without inversion symmetry (T_c = 0.75 K, T_N = 2.2 K) [1], however, distinguished by a SC order parameter which is composed of spin-singlet and spin-triplet components, assuring extraordinarily large upper critical field values.

In the present work, experimental and theoretical findings made on strongly correlated electron system CePt₃Si are discussed and compared with novel Ba, Sr [2] and Mo [3] based superconductors which miss both, inversion symmetry and strong electron correlations. These preconditions set the stage for reliable electronic structure calculations, which prove the splitting of electronic bands due to missing inversion symmetry. 

[1] E. Bauer et al., Phys. Rev. Lett. 92, 027003 (2004).
[2] E. Bauer et al., Phys. Rev. B 80, 064504 (2009).
[3] E. Bauer et al., Phys. Rev. B 82, 064511 (2010).