Events
Past events can be found in the archive.
Internal users can find the list of upcoming seminar presentations and the seminar dates to be booked in the E134 Colab Space., opens an external URL in a new window
07. October 2025, 16:00 until 17:00
Peter Jacobson, School of Mathematics and Physics, The University of Queensland, Brisbane/Australia
Seminar
Introducing superconductivity into group IV elements by doping has long promised a pathway to introduce quantum functionalities into well-established semiconductor technologies. Recent progress with non-equilibrium hyperdoping has shown superconductivity in C, Si, and Ge, but the role of disorder and dopant clustering has obscured the origin of this effect. I will present our work on epitaxial growth of gallium-hyperdoped germanium films and trilayer heterostructures by molecular beam epitaxy. These films reach extreme hole concentrations, via nearly 18% Ga substitution, and display superconductivity with a transition temperature of 3.5 K. Using synchrotron X-ray absorption and scattering, we find that Ga atoms incorporate substitutionally in the Ge lattice, introducing a slight tetragonal distortion. First-principles calculations support these findings and point to the formation of a narrow band that enables superconductivity. Together, these results establish hyperdoped Ga:Ge as a structurally ordered superconductor–semiconductor platform suitable for quantum technologies.
J.A. Steele, P.J. Strohbeen, C. Verdi, A. Baktash, A. Danilenko, Y.-H. Chen, J. van Dijk, F.H. Knudsen, A. Leblanc, D. Perconte, L. Wang, E. Demler, S. Salmani-Rezaie, P. Jacobson, J. Shabani, “Superconductivity in Substitutional Ga-Hyperdoped Ge Epitaxial Thin Films” Nature Nanotechnology (in press), arXiv:2412.15421v2
Event details
- Event location
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SEM.R. DB gelb 05 B
1040 Wien
Wiedner Hauptstraße 8-10/E134 - Organiser
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IAP
Manuela Marik
marik@iap.tuwien.ac.at - Public
- Yes
- Entrance fee
- No
- Registration required
- No