Congrats to Prof. Rzchowski on his retirement!

Posted on June 9, 2025

Mark Rzchowski

Congrats to Prof. Mark Rzchowski who has announced his retirement, effective January 17! Rzchowski is a condensed matter experimentalist who joined the department as an assistant professor in 1992 and has been a full professor since 2004. He served as Associate Chair for Undergraduate Program and Academic Affairs from 2008-10 and again from 2011-24.

When Rzchowski arrived to UW–Madison, high-temperature superconductivity had recently been discovered, and his early research largely centered on that topic, focusing on novel measurements of their fundamental physical properties.

“But I soon moved in different directions, collaborating with Chang-Beom Eom, a new faculty member in materials science and engineering expert in thin film growth,” Rzchowski recalls. “He had been working in superconductivity but had been branching out into some new systems, and we moved together in those directions.”

Rzchowski and Eom have collaborated for over two decades now, pairing forefront growth and manipulation of crystalline thin films with state-of-the art measurement approaches. Their collaboration has resulted in over 70 co-authored papers largely focused on quantum correlations and topologies in complex oxide thin-film materials. In spintronics, a technology that takes advantage of the intrinsic quantum spin state of an electron to substitute spin currents for the charge currents in “elec”tronics, they developed an all-thin-film membrane-based system that demonstrated an intrinsic coupling between voltage and spin. This helped to address a persistent problem in spintronics, namely better controlling magnetism at the nanoscale: the extreme thinness of the material allows low operating voltages to control the spin properties.

In another spintronics study in 2023, Rzchowski and Eom demonstrated uniquely oriented thin films of oxide crystals that controls the natural symmetry of the crystals, allowing them to produce vastly more useful spin currents — a critical step forward in advancing next-gen computer memory devices.

“I am so lucky to have known Mark — as a collaborator, colleague, and friend,” Eom says. “His brilliance as a scientist and kindness as a person will stay with me. I wish him happiness and fulfillment in the years ahead and I hope to continue sharing the joys of life for many years.”

two men stand in front of lab equipment — Chang Beom-Eom (left), a professor of materials science and engineering, and Mark Rzchowski, a professor of physics, in the lab. Photo: Joel Hallberg.

In 2022, Rzchowski was elected a Fellow of the American Physical Society for “pioneering discoveries and understanding of physical principles governing correlated complex materials and interfaces, including superconductors, correlated oxide systems multiferroic systems, and spin currents in noncollinear antiferromagnets.” He was nominated by the Division of Materials Physics.

Rzchowski has provided decades of service to the department, some of this time as associate chair. In this role, he led the redevelopment of several of the large courses, for example hiring course coordinators to provide consistency. He also was largely involved in the overhaul of algebra-based Physics 103 and 104, supported by the provost’s REACH initiative. REACH is designed to give students as many chances as possible to actively engage with physics principles and ideas, and to collaborate in group settings. An assessment of the program’s implementation showed a significant increase in concept mastery in these . He has represented the department at conferences presenting the REACH implementation and analysis of learning outcomes.

In March 2020, Rzchowski successfully led the transition of every course to all-online instruction when the Covid-19 pandemic abruptly sent everyone off campus, then to hybrid online/in-person instruction as students slowly returned. More recently, he helped leverage what was learned from those semesters into offering the summer session of Physics 103, and, now this year, Physics 104, as fully online courses. These online offerings have more than tripled summer enrollments — both UW–Madison students as well as visiting students.

Rzchowski was also chair of the department’s space committee in the early 2000s and oversaw the design of new laboratory and office space in Chamberlin Hall, and the transition from Sterling Hall to Chamberlin .

Prof. Emerit Bob Joynt, who overlapped with Rzchowski as associate chair when Joynt served as department chair from 2011-2014, says: “I worked closely with Mark Rzchowski for over 30 years. Of all my colleagues, he was the one whose advice I valued most, and the one who could most be trusted to follow through on everything he ever promised (which was a lot). He was not only a talented researcher, but he also was very generous with his time for the department, particularly the teaching program. He always did the jobs that were the most needed, usually those that were also the most thankless. So now, one last time, thank you Mark!”

Prof. Mark Eriksson, who served as department chair from 2021-2024, also overlapping with Rzchowski’s tenure as associate chair, says: “Mark Rzchowski made many contributions during his career in teaching research and service. In this last category for many years Mark served in the essential role of Associate Chair for Academic Affairs in which he solved — semester after semester — the complex riddle of matching instructors to courses in an optimal way.

— By Sarah Perdue, department of physics. Adam Malecek and Jason Daley of the College of Engineering contributed to this story

Victor Brar earns NSF CAREER award

Posted on October 13, 2023

Congrats to associate professor Victor Brar on earning an NSF CAREER award! CAREER awards are NSF’s most prestigious awards in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.

For this award, Brar will study the flow of electrons in 2D materials, or materials that are only around one atom thick. His group has already shown that when they applied a relatively old technique — scanning tunneling potentiometry, or STP — to 2D materials such as graphene, they could create unexpectedly high-contrast images, where they could track the movement of individual electrons when an electric current was applied. They found that electrons flow like a viscous fluid, a property that had been predicted but not observed directly.

“So now instead of applying electrical bias, we’ll apply a thermal bias, because we know things move from hot to cold, and then image how [electrons] move in that way,” Brar says. “Part of what’s driving this idea is that Professor Levchenko has predicted that if you image the way heat flows through a material, it should also behave hydrodynamically, like a liquid, rather than diffusive, which is how you might imagine it.”

One motivation for this research is to better understand the general flow of fluids, a problem that is often too complex for supercomputers to solve correctly. Because STP visualizes the fluid-like flow of electrons directly, Brar envisions this work as potentially providing a way of solving fluid mechanics problems by directly imaging flow, without the need of simulations, similar to what is done in wind tunnels.

“Also, there are these predicted phases of electrons that no one has observed before,” Brar says. “We want to be the first to observe them.”

In addition to an innovative research component, NSF proposals require that the research has broader societal impacts, such as working toward greater inclusion in STEM or increasing public understanding of science. Brar’s group is using haptic pens, devices that are commonly used in remote trainings for surgeons and in the gaming community because they give a gentle push back that mimics a realistic touch. By attaching the haptic pen to a scanning tunneling microscope (STM), people holding the pen can “feel” the individual atoms and surfaces that the STM is touching.

“We think materials science is one of those areas where feeling the forces that hold matter together may provide more intuitive than looking at equations,” Brar says. “We’re making virtual crystal lattices that you can touch with the haptic pen and feel how the atoms fix together, but we’re also making it so you can feel the different forces of the different atoms used.”

Brar plans to introduce the haptic pen and atom models into Physics 407 and develop a materials science module for the UW Alumni Association’s Grandparents University. And because the haptic pen relies almost entirely on touch, Brar plans to work with the Wisconsin Council of the Blind and Visually Impaired to improve access to materials science instruction for people with vision impairments.

Alex Levchenko, Mark Rzchowski elected Fellows of the American Physical Society

Posted on October 19, 2022

Congratulations to Profs. Alex Levchenko and Mark Rzchowski, who were elected 2022 Fellows of the American Physical Society!

Levchenko was elected for “broad contributions to the theory of quantum transport in mesoscopic, topological, and superconducting systems.” He was nominated by the Division of Condensed Matter Physics.

Rzchowski was elected for “pioneering discoveries and understanding of physical principles governing correlated complex materials and interfaces, including superconductors, correlated oxide systems multiferroic systems, and spin currents in noncollinear antiferromagnets.” He was nominated by the Division of Materials Physics.

APS Fellowship is a distinct honor signifying recognition by one’s professional peers for outstanding contributions to physics. Each year, no more than one half of one percent of the Society’s membership is recognized by this honor.

See the full list of 2022 honorees at the APS Fellows archive.