Physics 838 Graduate Student Seminar

In 1990, a seminar was initiated for QMC (formerly CNAM/CSR) graduate students in order to present their research to the other students, postdocs, and faculty in the Center. In addition to fostering a rich, collaborative environment in which students learn about the breadth and scope of research being done in QMC, the idea of this series is to teach several crucial skills to our students:

1) How to present their research in a clear and time-efficient way to an audience that was not expert in their area of research;

2) How to best answer questions during their presentations;

3) How to ask good questions when in an audience (or interview), in particular about research beyond their own narrow PhD topic.

In this seminar, students submit formalized feedback to each weekly presenter, providing informative information about presentation style, research content and tips for improvement.

Best Speaker Awards

At the end of each term, a cash prize award is given for the best student and postdoc presentations based on class feedback scores. Previous winners are listed here:

2025 (spring)  Jarryd Horn (student)

2024 (fall) Jared Erb (student)

2023 (fall) Jared Erb (student), Peter Czajka (postdoc)

2022 (fall) Sungha Baek (student), Keenan Avers (postdoc)

2020 (fall) Shukai Ma 

2019 (spring) Rui Zhang (student), Tarapada Sarkar (postdoc)

2018 (fall) Chris Eckberg (student), Jen-Hao Yeh (postdoc)

2015 Paul Syers, Jasper Drisko

2014 Sean Fackler, Paul Syers,

2013 Kevin Kirshenbaum, Kirsten Burson

2012 Baladitya Suri, Kristen Burson

2011 (fall) Sergii Pershoguba, Ted Thorbeck

2011 (spring) Anirban Gangopadhyay, Baladitya Suri

2010 (fall) Christian J. Long, Tomasz M. Kott

2010 (spring) Tomasz M. Kott, Kevin Kirshenbaum

2009 (fall) Arun Luykx, Jen-Hao Yeh

PHYS838C Seminar: Nicholas Crombie

Calendar
Physics 838 Seminar
Date
12.01.2025 4:00 pm - 5:00 pm
Location
John S. Toll Room 1201

Description



Title: Evolution of superconductivity and magnetic order in the half-Heusler series Y1-xYbxPtBi

Abstract: The noncentrosymmetric cubic series RPtBi (R = rare earth) hosts a range of exotic phases, including unconventional superconductivity, nontrivial topological band structures, and magnetic order. Notably, YPtBi exhibits superconductivity below Tc = 0.77 K with an unusually high critical field (Hc2 = 1.5 T), while YbPtBi demonstrates heavy fermion behavior and undergoes an antiferromagnetic transition at TN = 0.44 K. Additionally, YPtBi is a low-carrier semimetal (n ≈ 2 ×1018􀯗cm-3) with evidence of j = 3/2 electronic states. To investigate how the heavy fermion behavior and antiferromagnetism influence the high-spin superconductivity of YPtBi, I will synthesize single bulk crystals of the Y1-xYbxPtBi series using the metallic flux method and confirm the Yb concentration using magnetic susceptibility and x-ray fluorescence measurements. I will report on the evolution of semimetallic behavior, superconducting transition temperature (Tc), and magnetic order (TN) across the series using resistivity measurements in an adiabatic demagnetization refrigerator (ADR). I will also measure the crystals magnetoresistance, longitudinal resistivity, and hall resistivity to determine the carrier concentrations and mobilities across the series. Additionally, heat capacity measurements provide insight into the development of heavy fermion behavior as a function of Yb concentration.


Advisor: Paglione