0-π phase transition in hybrid superconductor-InSb nanowire quantum dot devices

Research output: Contribution to journalArticle

Abstract

Hybrid superconductor-semiconducting nanowire devices provide an ideal platform to investigating interesting intragap bound states, such as the Andreev bound states (ABSs), Yu-Shiba-Rusinov (YSR) states, and the Majorana bound states. The competition between Kondo correlations and superconductivity in Josephson quantum dot (QD) devices results in two different ground states and the occurrence of a 0-π quantum phase transition. Here we report on transport measurements on hybrid superconductor-InSb nanowire QD devices with different device geometries. We demonstrate a realization of continuous gate-tunable ABSs with both 0-type levels and π-type levels. This allow us to manipulate the transition between the 0 and π junction and explore charge transport and spectrum in the vicinity of the quantum phase transition regime. Furthermore, we find a coexistence of 0-type ABS and π-type ABS in the same charge state. By measuring temperature and magnetic field evolution of the ABSs, the different natures of the two sets of ABSs are verified, being consistent with the scenario of phase transition between the singlet and doublet ground state. Our study provides insight into Andreev transport properties of hybrid superconductor-QD devices and sheds light on the crossover behavior of the subgap spectrum in the vicinity of the 0-π transition.

Details

Authors
Organisations
External organisations
  • Peking University
  • Australian National University
  • Institute of Electronics, Microelectronics and Nanotechnology (IEMN)
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Condensed Matter Physics
Original languageEnglish
Article number014515
JournalPhysical Review B
Volume95
Issue number1
Publication statusPublished - 2017 Jan 20
Publication categoryResearch
Peer-reviewedYes