Editor’s Note – Engineering Professor Herbert Kroemer’s contribution to the world of electronics has been immeasurable. His lifetime of effort was rewarded in October with the Nobel Prize in physics. This article, the third in a four-part series, looks at Kroemer’s life and his effect on both the field and the school. Tomorrow’s article will examine the impact of the Nobel Prize on the university, and the effect these laureates have had on UCSB’s growing academic reputation.
Electrical and computer engineering Professor Herbert Kroemer invented the last 10 years. His work is at the core of everything from cellular phones, to satellites, to the fiber-optic cables rewiring the world.
Those are the kind of things they give people Nobel Prizes for.
During his 55-year journey from high school student in postwar Germany to recipient of science’s highest prize, Kroemer helped transform UCSB into a premier research university.
“He is, without a doubt, an intellectual superpower,” electrical and computer engineering Professor Umesh Mishra said. “To have somebody like that in the department is essential. He can serve in the capacity of having not only the wisdom of many years in the field, but also the wisdom that comes from being highly intelligent.”
A Prank Call From Stockholm?
Kroemer’s phone rang at 2:30 a.m. on Oct. 10.
“I had thought the evening before, more as a joke than anything else, wouldn’t it be kind of funny if I were called in the middle of the night,” Kroemer said.
Waking up, Kroemer said he first worried that something had happened to one of his five children.
“This is Stockholm,” said a voice on the other end of the line.
“I thought some students were playing a prank on me, because things like this have happened,” Kroemer said. “Then I was told that I had 15 minutes to get ready because in 15 minutes they would announce it to the public. … Twenty minutes later, all hell broke loose.”
As the sun rose over different parts of the world, more calls came, starting with Kroemer’s native Germany, the East Coast and then California.
“Then Henry [Yang], the chancellor, called,” Kroemer said. “My first reaction was, ‘I’ve got to hide.’ But then the chancellor called and said, ‘You cannot hide. You have to come. We have a press conference at 10:30.’ ”
Teenage Physics Lecturer
Kroemer, 72, gave his first physics lecture over 50 years ago, when he was still in high school. His school had been converted into a hospital during World War II, which allowed it to escape Allied bombs and the Soviet army. When the school reopened, his physics teacher enlisted Kroemer and another boy to help him with the science equipment, which had been kept safely in a storeroom.
“We had a ball, the three of us,” Kroemer said. “So then, he actually encouraged us to prepare the lectures for us. That went even further and he said, ‘Why don’t you give the lecture, and I sit down?’ ”
Initially, Kroemer’s interest wasn’t physics. “It probably started out with an interest in chemistry, but the way chemistry was taught in those days, they had you memorize 150 or a thousand different chemical reactions with no systematic principal behind it,” he said. “It was a monumental bore.”
In physics, he found there were basic principles that could be applied to a host of different situations. Physics, however, changed his approach to a math class taught by the same instructor.
“I was full of myself because I knew all of that stuff already, so I was telling all the students shortcuts through the work … basically disrupting the class,” he said. “[The teacher] was a small guy, but he knew how to handle people. He said, ‘Kroemer, I’ll make you a deal. I cannot really relieve you from attendance, but I’ll let you not turn in your homework, provided you do your physics, so long as you keep your mouth shut.’ ”
Heterostructures for Everything
Kroemer’s love of physics earned him a Ph.D., sent him to work in a number of German and American laboratories, and led to a job teaching physics at the University of Colorado. In 1976, when Kroemer felt it was time to leave Colorado, UCSB offered him a job.
“Back in ’76, this looked like a Mickey Mouse place,” he said. “But the transformation since has been simply staggering.”
“He formed the nucleus of a group,” said Larry Coldren, director of UCSB’s Optoelectronic Center. “[We] built this into what is widely considered the number-one group in the world in optoelectronics and compound semiconductor devices. Herb was at the root of all that.”
Kroemer’s heterostructure transistors, the backbone of modern electronics, operated at 100 times the speed of their predecessors. In a heterostructure transistor, two layers with different densities of electrons exist on either side of a third, lattice-shaped layer. When electrons try to migrate through, the lattice emits a photon, which acts as an information signal. Such transistors are at the heart of products like cell phones.
In 1963, Kroemer and Russian scientist Zhores Alferov, who was co-recipient of the 2000 physics Nobel Prize, proposed a heterostructure laser, operating on similar principles as the transistors. The lasers form the basis for the technology found in fiber optic cables, CDs, laser pointers and bar-code readers.
“Previously,” Kroemer said, “if you send the electrons one way, they all go the opposite way, so you say, ‘Aha. You two guys go together. You belong together. We need you together.’ ”
A Meticulous Man
Kroemer doesn’t only ask a lot of his electrons.
“As an individual, he is meticulous in his demand for excellence,” Coldren said. “He expects excellence in his students. … He’s uncompromising in his demand for discipline, in the way people do their homework, even the format in which they put things on a piece of paper. He likes to teach good habits, good rules. Students usually appreciate that after the fact, but maybe not during it.”
That demand for quality, Coldren said, has helped Kroemer elevate the level of research on campus.
“Herb has always had a high standard, a high expectation of his peers,” Coldren said. “He has a lot of respect for people he feels have made major contributions. He sometimes has less tolerance for mediocrity than some people might, and he tends to let you know that. I think he’s very well liked, but he’s in some sense feared. But that’s the mark of an excellent professor – having standards and living by them. … I have the utmost respect for him. He’s been a real help and mentor to me over the years.”