UW Physics Student Research Colloquium 2024

The University of Wisconsin–Madison Department of Physics is pleased to host the second-annual Physics Department Special Colloquium for Graduate Student Research on Friday, April 5, 2024!

This event will feature talks from UW-Physics graduate students and posters from undergraduate students that showcase the phenomenal and exciting research of students happening throughout the department. This event is open to all undergraduate students, graduate students, faculty, and staff in the Department of Physics as well as anyone interested in hearing about the amazing work happening throughout the department! This is a drop-in event, so come and go as you need.

Please see the schedule and details below related to poster presentations, research talks, and opportunities for breaks and networking.

Colloquium Agenda

Time	Speaker/Event	Location	Presentation Title
1:00 PM – 2:00 PM	Undergraduate Poster Sessions	Chamberlin Hall Lobby	Nathan Wagner, Ruben Aguilo Schuurs, Lewis Ballard, Caleb Youngwerth, M Clark, Lucy Steffes
1:30 PM – 4:15 PM	Refreshments available	Chamberlin Hall Lobby
2:30 PM	Welcome	2241 Chamberlin	Mark Eriksson, UW Physics Department Chair
2:35 PM	Puxin Lin	2241 Chamberlin	Charged radiation of extremal black holes
2:55 PM	Joy Hasan	2241 Chamberlin	Theory of superconducting diode effect in helical superconductors
3:15 PM	Paul Buttles	2241 Chamberlin	Winning for Losing: Quantum Parrondo’s Paradox
3:35 PM	Julia Sheffler	2241 Chamberlin	Searching for Young, Nearby Alien Worlds
3:55 – 4:15 PM	Reception	Chamberlin Hall Lobby

Puxin Lin

Physics PhD Student

Research Advisor: Prof. Gary Shiu

Joy Hasan

Physics PhD Student

Research Advisor: Alex Levchenko

Paul Buttles

MSPQC Student

profile photo of Julia Sheffler

Julia Sheffler

Physics PhD Student

Research Advisor: Prof. Melinda Soares-Furtado

Charged Radiation of Extremal Black Holes

Extremal black holes are intriguing objects exhibiting both strong gravitational and quantum effects – they are test beds for a consistent theory of quantum gravity. Radiation processes open up channels for black holes to decay, revealing information of the black holes and bounds on the underlying theory, while also creating possible signals for observations. In this talk, I will introduce the radiation and decay of black holes and their implications.

Theory of Superconducting Diode Effect in Helical Superconductors

In helical superconductors where both time reversal and inversion symmetries are broken, the supercurrent is nonreciprocal: the superconductor is superconducting in one direction and resistive in the other. We study the Ginzburg-Landau (GL) theory of this superconducting diode effect in planar helical Rashba superconductors where time reversal symmetry is broken by the external magnetic field and the inversion symmetry is broken by the combined effect of Rashba type spin-orbit interaction and asymmetry of the crystal potential in the direction perpendicular to the two-dimensional plane. We derive the analytical expression of the superconducting diode coefficient proportional to the difference in the magnitude of the nonreciprocal critical currents to leading order in magnetic field and correct previous theoretical works where the GL free energy was not expanded properly in powers of the superconducting order parameter and the Cooper pair momentum to include relevant terms resulting in incorrect prediction of the superconducting diode effect.

Winning for Losing: Quantum Parrondo’s Paradox

Parrondo’s Paradox is a counterintuitive result from classical game theory in which two losing games are combined to form one winning strategy. In quantum game theory, it has been demonstrated that quantum mechanical effects can be employed to construct variants of the paradox not possible classically. Here, we present a novel quantum Parrondo game that specifically makes use of entanglement to produce a winning strategy. We demonstrate that this effect persists even when strategies are selected at random.

Searching for Young, Nearby Alien Worlds

We have a solid foundation for how life functions on Earth, but we can make only educated guesses about life on other planets. As missions such as Kepler and the Transiting Exoplanet Survey Satellite (TESS) discover more and more planets outside our solar system, we begin to study exoplanets, and the life they may support, more directly. The star HD 63433 is a bright, nearby, and young (~400Myr) host to three planets, including the nearest detected Earth-sized planet (HD 63433d), within the Ursa Major comoving group (UMa). Young planetary systems such as HD63433 form critical test cases for understanding planetary and stellar evolution. Yet, of the over 5500 confirmed planets, only about 70 are known to have ages less than 500Myr, motivating a comprehensive search of UMa members for planetary companions. Further constraining the membership and age of UMa provides contextual foundation for this young Earth-sized exoplanet and any future planets discovered within the UMa system.