Focus Magazine, Boise State UniversityRESEARCH
PHYSICS PROFESSOR HANNA STUDIES
HOW ELECTRONS BEHAVE
Charles Hanna works with a student on a physics concept. By Janelle Brown
The tools that Boise State physics professor Charles Hanna uses to conduct his research are deceptively simple. A chalkboard. A computer. Paper and pencil.
"It's important to have an eraser so you can make changes," Hanna says. "But the really important stuff, you keep in your head."
Hanna is in the second year of a $35,000 national grant to study an aspect of the quantum Hall effect, which involves the way electrons change their behavior in magnetic fields.
He scribbles down equations and runs numerical calculations on his computer, but the real brunt of his work is done mentally. "The answer seems obvious, once you find it," Hanna says. "But it can look completely impossible until you do."
If the quantum Hall effect sounds familiar, there's a reason. Three scientists, including Robert Laughlin, Hanna's former faculty adviser at Stanford University, won the 1998 Nobel Prize in Physics for their work on the phenomenon.
They discovered that a single layer of electrons placed in a strong magnetic field at a temperature near absolute zero can condense into a new type of quantum fluid with fractionally charged particles.
Hanna's research is related. He's studying what happens when more than one layer of electrons, separated by atomic distances, are subjected to the same conditions of a strong magnetic field and extremely low temperatures.
He's discovered that when the two layers have an unequal number of electrons, then the quantum Hall effect can become stronger. "Most people thought that in an unbalanced state, the quantum Hall effect got weaker. But it turns out it's just the opposite," he says.
Hanna hopes his research will provide additional insight into how the forces between electrons in semiconductors affect their group behavior.
"The effects of quantum mechanics and interactions between electrons get more important as semiconductor devices get smaller," he says. "And they get smaller all the time."
Hanna joined Boise State's faculty in 1996 and won a nationally competitive Cottrell College Science Award from the Research Corp. last year. He hopes to secure additional funding when the grant ends in 1999.
Hanna says his intense curiosity fuels his research and teaching. "There is real excitement in discovering how the physical world works," he says.
