Join us remotely for a joint Special Colloquium between the College of Science, College of Engineering & Quantum Materials and Sensing Institute on Friday, February 23rd, 2024. 

Speaker: Dr. Md Shafayat Hossain (Princeton University)

Hosts: Arun Bansil and Matteo Rinaldi

When: Friday, February 23rd, 2024 @ 11AM

Title: Room-temperature and many-body quantum states in topological materials

Abstract: Topological states of matter combine quantum physics with topology—a branch of mathematics that explores geometric properties preserved under deformation. Quantum topology can lead to incredible properties. For instance, in a topological insulator, conducting edge states exist within an insulating bulk. Despite continuing progress, the search for such new quantum phases remains a central theme of condensed matter physics. In this talk, I will introduce two of the most sought-after quantum states—room-temperature topology and topological exciton insulator. I will first discuss our spectroscopic observation of topological edge states in Bi4Br4. I will show that the topological states, which typically can only be observed at temperatures around absolute zero, survive here at room temperature. I will also show how we probe the quantum transport response of this edge state using quantum interference. These observations mark the first steps in demonstrating the potential of topological materials for energy-saving applications. In the second part of my talk, I will discuss our discovery of a unique topological state in Ta2Pd3Te5. Here, the Coulomb interactions pair fermions (electrons and holes) into bosons (excitons), leading to a superfluid condensate state in the bulk while hosting topological edge states on the boundary. Finally, I will touch upon how these discoveries suggest exciting possibilities. This includes new devices and experimental techniques to discover the fundamental physics of topological quantum matter, opening doors for more efficient room-temperature devices and quantum information technology.

Zoom meeting link: https://northeastern.zoom.us/j/99842535071