Tracking a spin-polarized superconducting bound state across a quantum phase transition
Abstract 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 obse...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2024-01-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-024-44708-2 |
| _version_ | 1797355623798538240 |
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| author | Sujoy Karan Haonan Huang Alexander Ivanovic Ciprian Padurariu Björn Kubala Klaus Kern Joachim Ankerhold Christian R. Ast |
| author_facet | Sujoy Karan Haonan Huang Alexander Ivanovic Ciprian Padurariu Björn Kubala Klaus Kern Joachim Ankerhold Christian R. Ast |
| author_sort | Sujoy Karan |
| collection | DOAJ |
| description | Abstract 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. The excitation spectrum changes from featuring two peaks in the doublet (free spin) state to four peaks in the singlet (screened spin) ground state. We also identify a transition regime, where the YSR excitation energy is smaller than the Zeeman energy. We thus demonstrate a straightforward way for unambiguously identifying the ground state of a spin-1/2 YSR state. |
| first_indexed | 2024-03-08T14:13:50Z |
| format | Article |
| id | doaj.art-17db9f22afc8420388aa025c129b538f |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-03-08T14:13:50Z |
| publishDate | 2024-01-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-17db9f22afc8420388aa025c129b538f2024-01-14T12:28:47ZengNature PortfolioNature Communications2041-17232024-01-011511710.1038/s41467-024-44708-2Tracking a spin-polarized superconducting bound state across a quantum phase transitionSujoy Karan0Haonan Huang1Alexander Ivanovic2Ciprian Padurariu3Björn Kubala4Klaus Kern5Joachim Ankerhold6Christian R. Ast7Max Planck Institute for Solid State ResearchMax Planck Institute for Solid State ResearchInstitute for Complex Quantum Systems and IQST, Universität UlmInstitute for Complex Quantum Systems and IQST, Universität UlmInstitute for Complex Quantum Systems and IQST, Universität UlmMax Planck Institute for Solid State ResearchInstitute for Complex Quantum Systems and IQST, Universität UlmMax Planck Institute for Solid State ResearchAbstract 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. The excitation spectrum changes from featuring two peaks in the doublet (free spin) state to four peaks in the singlet (screened spin) ground state. We also identify a transition regime, where the YSR excitation energy is smaller than the Zeeman energy. We thus demonstrate a straightforward way for unambiguously identifying the ground state of a spin-1/2 YSR state.https://doi.org/10.1038/s41467-024-44708-2 |
| spellingShingle | Sujoy Karan Haonan Huang Alexander Ivanovic Ciprian Padurariu Björn Kubala Klaus Kern Joachim Ankerhold Christian R. Ast Tracking a spin-polarized superconducting bound state across a quantum phase transition Nature Communications |
| title | Tracking a spin-polarized superconducting bound state across a quantum phase transition |
| title_full | Tracking a spin-polarized superconducting bound state across a quantum phase transition |
| title_fullStr | Tracking a spin-polarized superconducting bound state across a quantum phase transition |
| title_full_unstemmed | Tracking a spin-polarized superconducting bound state across a quantum phase transition |
| title_short | Tracking a spin-polarized superconducting bound state across a quantum phase transition |
| title_sort | tracking a spin polarized superconducting bound state across a quantum phase transition |
| url | https://doi.org/10.1038/s41467-024-44708-2 |
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