Hot Topics in Quantum Nanoscience - Harold Hwang (Stanford) "Dilute superconductivity in SrTiO3"



10:30 - 12:00 hrs.


Delft University of Technology, TNW (building 22), Lorentzweg 1, Delft, room F


Hot Topics in Quantum Nanoscience

Course Content: Speakers from all over the world will be asked to present pedagogical introductions to their field with an emphasis on basic concepts. Besides such an introductory lecture open for everybody, the participants of this course will have an additional discussion with the speaker discussing a recent paper and the holy grails of the field.

Exemplary topics are topological insulators, mesoscopic quantum gravity, string theory for condensed matter, measurement-based quantum computing, quantum-limited sensors, Majorana Fermions, fast-light with single photons, etc., etc. For an overview of our previous sessions, please click here.

Audience: All are invited to attend the tutorial, a 45-minute lecture. The second part of the hot topics session will be reserved as a discussion session for the lecturer with the registered class of PhD students and postdocs only.

Registration: please register for this session by filling in the form in the below. The data we collect are used for organizational purposes only and won't be stored longer than absolutely necessary. For more details, see our privacy statement.

Preparation: PhD students who have registered for the hot topics course need to prepare for the session by reading the article that can be found below.

Date: Friday 15 November 2019.

Speaker: Prof. dr. Harold Hwang

Title: "Dilute superconductivity in SrTiO3"

Abstract: The nature of superconductivity in the dilute semiconductor SrTiO3 has remained an open question for over half a century. Thin film heterostructures provide new opportunities to examine SrTiO3 superconductivity using a newly developed method for engineering band alignments at oxide interfaces to access the electronic structure of Nb-doped SrTiO3 using high-resolution tunneling spectroscopy. While we observe strong coupling to the highest-energy longitudinal optic phonon consistent with λ ~ 1, the superconducting gap is found to be in the weak-coupling limit of BCS theory, i.e. λ_BCS ~ 0.1. This discrepancy arises in the context of an unusual anti-adiabatic condition for superconductivity in SrTiO3 (Fermi energy < Debye energy), which we find precisely bounds the superconducting dome. 

Host: Dr. Tim Taminiau

Location:  Delft University of Technology, TNW (building 22), Lorentzweg 1, Delft.

Room: Room F (F105)

Time: 10:30 - 12:00 hrs.

Required reading: POLARONIC BEHAVIOR IN A WEAK COUPLING SUPERCONDUCTOR A. G. Swartz, H. Inoue, T. A. Merz, Y. Hikita, S. Raghu, T. P. Devereaux, S. Johnston and H. Y. Hwang, Proc. Natl. Acad. Sci. U. S. A. 115, 1475-1480 (2018).