Tracking a Spin-Polarized Superconducting Bound State across a Quantum Phase Transition
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2023
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866929295707865088 |
|---|---|
| author | Karan, Sujoy Huang, Haonan Ivanovic, Alexander Padurariu, Ciprian Kubala, Björn Kern, Klaus Ankerhold, Joachim Ast, Christian R. |
| author_facet | Karan, Sujoy Huang, Haonan Ivanovic, Alexander Padurariu, Ciprian Kubala, Björn Kern, Klaus Ankerhold, Joachim Ast, Christian R. |
| contents | The magnetic exchange coupling between magnetic impurities and a superconductor induce so-called Yu-Shiba-Rusinov (YSR) states which undergo a quantum phase transition (QPT) upon increasing the exchange interaction beyond a critical value. While the evolution through the QPT is readily observable, in particular if the YSR state features an electron-hole asymmetry, the concomitant change in the ground state is more difficult to identify. We use ultralow temperature scanning tunneling microscopy to demonstrate how the change in the YSR ground state across the QPT can be directly observed for a spin-1/2 impurity in a magnetic field. We observe a change in the excitation spectrum from the doublet ground state in the free spin regime (two spectral features) to the singlet ground state in the screened spin regime (four spectral features). We also identify a transition regime, where the YSR excitation energy is smaller than the Zeeman energy. We thus provide a straightforward way for unambiguously identifying the ground state of a spin-1/2 YSR state. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2304_02955 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Tracking a Spin-Polarized Superconducting Bound State across a Quantum Phase Transition Karan, Sujoy Huang, Haonan Ivanovic, Alexander Padurariu, Ciprian Kubala, Björn Kern, Klaus Ankerhold, Joachim Ast, Christian R. Superconductivity Mesoscale and Nanoscale Physics The magnetic exchange coupling between magnetic impurities and a superconductor induce so-called Yu-Shiba-Rusinov (YSR) states which undergo a quantum phase transition (QPT) upon increasing the exchange interaction beyond a critical value. While the evolution through the QPT is readily observable, in particular if the YSR state features an electron-hole asymmetry, the concomitant change in the ground state is more difficult to identify. We use ultralow temperature scanning tunneling microscopy to demonstrate how the change in the YSR ground state across the QPT can be directly observed for a spin-1/2 impurity in a magnetic field. We observe a change in the excitation spectrum from the doublet ground state in the free spin regime (two spectral features) to the singlet ground state in the screened spin regime (four spectral features). We also identify a transition regime, where the YSR excitation energy is smaller than the Zeeman energy. We thus provide a straightforward way for unambiguously identifying the ground state of a spin-1/2 YSR state. |
| title | Tracking a Spin-Polarized Superconducting Bound State across a Quantum Phase Transition |
| topic | Superconductivity Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2304.02955 |