applied math seminar, Wladimir Benalcazar, Department of Physics, Princeton U.
Event Type:
Seminar
Speaker:
Wladimir Benalcazar, Department of Physics, Princeton U.
Event Date:
Monday, September 20, 2021 -
3:30pm to 4:30pm
Location:
Zoom Meeting
Audience:
General PublicFaculty/StaffStudentsAlumni/Friends
Sponsor/s:
Pavel Lushnikov
Event Description:
Title: "Higher-order topological band theory"
Abstract:
In the presence of crystalline symmetries, certain topological insulators present a filling anomaly: a mismatch between the number of electrons in an energy band and the number of electrons required for charge neutrality. This seminar will show how a "corner-induced filling anomaly" is at the core of the bulk-boundary correspondence of higher-order topology in two dimensions. In crystalline insulators, the consequence of higher-order topology is the quantized fractionalization of corner electronic charge. I will discuss the connection between fractional corner charge and topological corner states. The latter is a feature that transcends insulators and allows for higher-order topological protection in superconductors and synthetic materials. In particular, I will discuss higher-order topological protection in crystalline photonic systems.
Short bio:
Wladimir Benalcazar obtained his PhD in physics at the University of Illinois at Urbana-Champaign in 2018, working with Prof. Taylor Hughes. There, he discovered a new type of topological phase of matter, "quantized electric multipole insulators" and developed the more general theory of "higher-order topological insulators". Some of the phases predicted by this theory have been observed in synthetic material platforms and real materials. For the past three years, he has been an Eberly Postdoctoral Fellow at the Pennsylvania State University, where he further developed the theory of "higher-order topological phases" and introduced the concept of "boundary-obstructed topological phases" and predicted the existence of bound states in the continuum in some of these phases, later verified experimentally by colleagues at Penn State. He is now a Moore Postdoctoral Fellow in the Department of Physics at Princeton University.
