At six years old, Jacek Furdyna boarded a train out of eastern Poland with his mother, deported into the Soviet interior after the 1939 invasion split his family apart and sent his father to a labor camp north of the Arctic Circle. Furdyna, who went on to become one of the world's leading experimental physicists in the study of magnetic semiconductors and a longtime professor at the University of Notre Dame, died on September 28, 2026, at 93.

The family's postwar road ran through Kazakhstan and Uzbekistan, then Iran, Iraq and Palestine, before Furdyna and his mother reunited with his father in the United Kingdom in 1947, according to a biography Purdue University published when it later awarded him an honorary doctorate. He immigrated to the United States in 1948 and settled with his parents in Chicago, where he attended Holy Trinity High School before earning a physics degree, summa cum laude, from Loyola University Chicago in 1955 and a doctorate in experimental solid-state physics from Northwestern University in 1960, with a thesis on the microwave Faraday effect in silicon and germanium.

He spent four years on the research staff of MIT's Francis Bitter National Magnet Laboratory before joining Purdue University's physics department in 1966. There, in 1969, he turned to diluted magnetic semiconductors, materials that combine ordinary semiconductor behavior with magnetism, and built the research program that would define his career, according to Physics Magazine, published by the American Physical Society.

In 1987 Furdyna joined the University of Notre Dame as the Aurora and Thomas Marquez Professor of Physics, where he spent decades studying epitaxially grown magnetic semiconductors and the quantum structures built from them. In 2012, working with Notre Dame colleague Xinyu Liu and Purdue physicist Leonid Rokhinson, he helped build a nanowire device pairing a semiconductor with a superconductor that produced one of the first clear experimental signatures of Majorana fermions, particles theorized in the 1930s and sought by physicists for generations, in a paper published in Nature Physics. "A key for achieving a structure of sufficient quality to display this signature was the process of molecular beam epitaxy," Furdyna said of the work at the time, Notre Dame's Department of Physics reported.

His research drew honorary doctorates from the University of Warsaw in 2002 and from Purdue in 2007, where the citation called him one of the most creative scientists in the world of semiconductors. In 2009 the Polish Academy of Sciences awarded him its Nicolaus Copernicus Medal, the academy's highest honor, for his contributions to new semiconductor materials, including magnetic semiconductors aimed at fast new computing functions. He was elected a Fellow of the American Physical Society, the Institute of Physics in the United Kingdom, and the American Association for the Advancement of Science, and in 2008 was named among the American Physical Society's first group of Outstanding Referees.

At Notre Dame his career ran alongside that of his wife, physicist Malgorzata Dobrowolska-Furdyna, who joined the faculty the same year he did and became the Rev. John Cardinal O'Hara, C.S.C. Professor of Physics and an associate dean in the College of Science. Furdyna kept working past formal retirement, presenting a condensed matter seminar on current-driven magnetization switching in ferromagnetic semiconductors at Notre Dame as recently as October 2024, two years before his death.

The magnetic semiconductor program Furdyna started at Purdue in the late 1960s outlasted his own tenure there, and the epitaxial growth and nanowire techniques he helped refine remain part of the toolkit researchers use in the search for practical spintronic and topological quantum devices. A child who crossed a continent as a refugee spent his working life coaxing new behavior out of crystals grown one atomic layer at a time, and the hundreds of papers, the students he trained, and the Notre Dame laboratory he helped build carry that work forward.