[2023.06.02] 14:00-15:30 ❘ Prof. Miguel A. Cazalilla (Donostia International Physics Center (DIPC)) : Cooper Pair Excitation Mediated by a Molecular Quantum Spin on a Superconducting Proximitized Gold Film
**************** Joint CTC Condensed Matter Seminar ****************
Title: Cooper Pair Excitation Mediated by a Molecular Quantum Spin on a Superconducting Proximitized Gold Film
Speaker: Prof. Miguel A. Cazalilla (Donostia International Physics Center (DIPC))
Start Date/Time: 2023-06-02 / 14:00 Taipei time
End Date/Time : 2023-06-02 / 15:30
Place: P512, 5F, 3rd General Building, Nat'l Tsing Hua Univ.
Host: Prof. Pochung Chen (NTHU)
Abstract:
Breaking a correlated pair in a superconductor requires an even number of fermions providing at least twice the pairing energy Δ.
Here, I will describe how a single tunneling electron can also excite a pair breaking excitation in a proximitized gold film in the presence of magnetic
impurities. Combining scanning tunneling spectroscopy with theoretical modeling, we have mapped the excitation spectrum of an Fe-porphyrin
molecule on the Au/V(100) proximitized surface into a manifold of entangled Yu-Shiba-Rusinov and spin excitations. Pair excitations emerge
in the tunneling spectra as peaks outside the spectral gap only in the strong coupling regime, where the presence of a bound quasiparticle
in the ground state ensures the even fermion parity of the excitation. Our results unravel the quantum nature of magnetic impurities
on superconductors and demonstrate that pair excitations unequivocally reveal the parity of the ground state. Time permitting,
I will provide further details of the theoretical justification for the model that accounts for these experimental observations [2].
REFERENCES:
[1] Stefano Trivini, Jon Ortuzar, Katerina Vaxevani, Jingchen Li, F. Sebastian Bergeret, MAC, and Jose Ignacio Pascual
Phys. Rev. Lett. 130, 136004 (2023).
[2] Jon Ortuzar, Jose Ignacio Pascual, F. Sebastian Bergeret, MAC, report arXiv:2304.14448 (2023).
Title: Cooper Pair Excitation Mediated by a Molecular Quantum Spin on a Superconducting Proximitized Gold Film
Speaker: Prof. Miguel A. Cazalilla (Donostia International Physics Center (DIPC))
Start Date/Time: 2023-06-02 / 14:00 Taipei time
End Date/Time : 2023-06-02 / 15:30
Place: P512, 5F, 3rd General Building, Nat'l Tsing Hua Univ.
Host: Prof. Pochung Chen (NTHU)
Abstract:
Breaking a correlated pair in a superconductor requires an even number of fermions providing at least twice the pairing energy Δ.
Here, I will describe how a single tunneling electron can also excite a pair breaking excitation in a proximitized gold film in the presence of magnetic
impurities. Combining scanning tunneling spectroscopy with theoretical modeling, we have mapped the excitation spectrum of an Fe-porphyrin
molecule on the Au/V(100) proximitized surface into a manifold of entangled Yu-Shiba-Rusinov and spin excitations. Pair excitations emerge
in the tunneling spectra as peaks outside the spectral gap only in the strong coupling regime, where the presence of a bound quasiparticle
in the ground state ensures the even fermion parity of the excitation. Our results unravel the quantum nature of magnetic impurities
on superconductors and demonstrate that pair excitations unequivocally reveal the parity of the ground state. Time permitting,
I will provide further details of the theoretical justification for the model that accounts for these experimental observations [2].
REFERENCES:
[1] Stefano Trivini, Jon Ortuzar, Katerina Vaxevani, Jingchen Li, F. Sebastian Bergeret, MAC, and Jose Ignacio Pascual
Phys. Rev. Lett. 130, 136004 (2023).
[2] Jon Ortuzar, Jose Ignacio Pascual, F. Sebastian Bergeret, MAC, report arXiv:2304.14448 (2023).