Zapraszamy do udziału w seminarium Wydziału Inżynierii Materiałowej i Fizyki Technicznej Politechniki Poznańskiej oraz Oddziału Poznańskiego Polskiego Towarzystwa Fizycznego, które odbędzie się 18 kwietnia 2024 r. o godz. 11:45. Pan prof. dr Roberto Lo Conte wygłosi seminarium pt. "Emergent topology in a superconducting hybrid system driven by an antiferromagnetic spin texture". Seminarium będzie transmitowane w systemie e-Meeting pod adresem: https://emeeting.put.poznan.pl/eMeeting/rys-gup-9is
Abstract
Emergent topology in a superconducting hybrid system driven by an antiferromagnetic spin texture
Roberto Lo Conte
Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
In the recent years, pioneering studies have been carried out on magnet/superconductor hybrid systems [1-4], motivated by their potential to host emergent quantum phases such as topological superconductivity [5]. So far, the attention has been mainly focused on hybrid systems with a ferromagnetic order [1,3,4,6], which are understood as gapped topological superconductors with a finite Chern number [7,8] defining the amount of end states and propagating edge modes. In my talk, I will discuss the discovery of a topological nodal-point superconducting phase in a hybrid system consisting of antiferromagnetic manganese (Mn) monolayer islands on top of the s-wave superconductor niobium (Nb) [9,10]. The novel topological superconducting phase was discovered via a low-temperature spin-polarized scanning tunneling microscopy and spectroscopy investigation. Low-energy edge modes are observed at the boundaries of the magnetic islands, separating the topological phase from the trivial one. In accordance to tight-binding calculations, it was found that the relative spectral weight of the edge modes depends on the edge’s atomic configuration, which is a fingerprint of the discovered topological superconducting state. These results establish the combination of antiferromagnetism and superconductivity as a novel route to design 2D topological quantum phases.
Roberto Lo Conte
Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
In the recent years, pioneering studies have been carried out on magnet/superconductor hybrid systems [1-4], motivated by their potential to host emergent quantum phases such as topological superconductivity [5]. So far, the attention has been mainly focused on hybrid systems with a ferromagnetic order [1,3,4,6], which are understood as gapped topological superconductors with a finite Chern number [7,8] defining the amount of end states and propagating edge modes. In my talk, I will discuss the discovery of a topological nodal-point superconducting phase in a hybrid system consisting of antiferromagnetic manganese (Mn) monolayer islands on top of the s-wave superconductor niobium (Nb) [9,10]. The novel topological superconducting phase was discovered via a low-temperature spin-polarized scanning tunneling microscopy and spectroscopy investigation. Low-energy edge modes are observed at the boundaries of the magnetic islands, separating the topological phase from the trivial one. In accordance to tight-binding calculations, it was found that the relative spectral weight of the edge modes depends on the edge’s atomic configuration, which is a fingerprint of the discovered topological superconducting state. These results establish the combination of antiferromagnetism and superconductivity as a novel route to design 2D topological quantum phases.
[1] S. Nadj Perge et al., Science 346, 602 (2014).
[2] H. Kim et al., Science Advances 4, eaar5251 (2018).
[3] A. Palacio-Morales et al., Science Advances 5, eaav6600 (2019).
[4] L. Schneider et al., Nature Physics 17, 943 (2021).
[5] J. Li et al., Nature Communications 7: 12297 (2016).
[6] S. Kezilebieke et al., Nature 588, 424 (2020).
[7] A. P. Schnyder, et al., Physical Review B 78, 195125 (2008).
[8] C. Chiu, et al. Review of Modern Physics 88, 035005 (2016).
[9] R. Lo Conte et al., Physical Review B 105, L100406 (2022).
[10] M. Bazarnik, R. Lo Conte et al., Nature Communications 14, 614 (2023).
