Nobel Prize-winning physicist and U.S. Secretary of Energy Steven Chu will return to Stanford University after he steps down from his cabinet position.

Chu, who previously served as the director of the Lawrence Berkeley National Laboratory from 2004 to 2009, will hold joint appointments in the Stanford department of physics and the School of Medicine’s department of molecular and cellular physiology.

“I would like to return to an academic life of teaching and research but will still work to advance the missions that we have been working on together for the last four years,” Chu said in a letter to the Department of Energy.

Chu earned a Ph.D. in physics from UC Berkeley in 1976. He joined the physics faculty at Stanford in 1987, where he won the 1997 Nobel Prize in Physics for his research on laser cooling. He was the director of the Lawrence Berkeley National Laboratory before becoming secretary of energy in 2009.

Chu will step down from his four-year term as secretary of energy when his successor is confirmed. President Barack Obama has yet to announce a replacement.