Events

R. G. Herb Condensed Matter Seminars

<< Fall 2022 Spring 2023 Summer 2023 >>
Subscribe your calendar or receive email announcements of events

Events During the Week of February 12th through February 19th, 2023

Monday, February 13th, 2023

No events scheduled

Tuesday, February 14th, 2023

Discovering and Engineering Two-Dimensional Magnetism and Superconductivity
Time: 10:00 am
Place: 5310 Chamberlin
Speaker: Tiancheng Song, Princeton
Abstract: Understanding and manipulating macroscopic quantum phenomena such as superconductivity and magnetism are crucial for future quantum science and technology. Two-dimensional (2D) materials and their van der Waals (vdW) heterostructures offer a promising platform to achieve this goal due to their exceptionally broad tunability. In this talk, I will highlight the potential of such a platform through two outstanding examples: 2D magnetism and 2D superconductivity. In the first part, I will talk about a series of emergent phenomena enabled by the vdW nature of 2D magnets, including (1) giant tunneling magnetoresistance enhanced by spin-filtering effects; (2) control of interlayer magnetism by tuning layer stacking; (3) novel moiré magnetism by twisting two layers of 2D magnets. In the second part, I will introduce a new probe to detect superconducting fluctuations down to millikelvin temperatures based on thermoelectric measurements of a monolayer nanoflake. I will discuss surprisingly unusual vortex Nernst signals, which reveal an unconventional superconducting quantum criticality in an electrically tunable 2D superconductor. Finally, I will conclude by highlighting unique opportunities for discovering and engineering new quantum materials and electronic phases in two dimensions.
Host: Victor Brar
Add this event to your calendar

Wednesday, February 15th, 2023

No events scheduled

Thursday, February 16th, 2023

Strange Metal Behavior in the Hall Coefficient of BaFe2(As,P)2
Time: 10:00 am
Place: 5310 Chamberlin
Speaker: Ian Hayes, University of Maryland
Abstract: Even after decades of research on the high-Tc cuprates, several parts of their phase diagrams remain mysterious, especially the normal state above Tc near optimal doping, a region commonly referred to as the strange metal phase. New avenues for studying this physics were opened up by the discovery of the iron-based high-Tc materials, which also exhibit strange metal characteristics, particularly a T-linear resistivity and a roughly 1/T Hall coefficient near optimal doping. In this talk I will present measurements of the Hall coefficient in phosphorous-doped BaFe2As2 in fields of up to 65 tesla, which is enough to suppress superconductivity even at optimal doping. These measurements reveal a striking parallel between the effects of increasing magnetic field and the effects of increasing temperature, a phenomenon that is reminiscent of the field-temperature scaling seen in the resistivity of this compound. This characteristic field dependence allows us to clearly identify the extent of strange metal physics in the entire phosphorous-doping phase diagram. Intriguingly, the presence of strange metal behavior in the Hall coefficient is directly related to the presence of the superconductivity across the phase diagram. I will discuss the implications of these observations for different approaches to the strange metal as well as the opportunities they present for future research.
Host: Victor Brar
Add this event to your calendar

Friday, February 17th, 2023

No events scheduled