Background

Lene Vestergaard Hau was born on November 13, 1959, in Vejle which is a town of about 50,000 inhabitants situated on the Vejle Fjord, northwest of Fredericia, on the east coast of Jutland. She did not come from a family with a background in science or mathematics: "Neither of my parents had any background in science. My father was in the heating business and my mother worked in a store. But both of them believed in giving me the same advantages as my brother, which was very important to my education."

Education

Mathematics was the subject Lene Hau liked best when at primary school and her achievements at this stage were so impressive that she was able to miss the final year of her primary education and enter directly into a gymnasium. She decided to study mathematics and physics at the University of Aarhus which was situated quite close to her hometown. At first, physics was not as interesting as she had expected, and she was more attracted to mathematics: "When I first entered Arhus University I was bored by physics. They just taught us thermodynamics and classical mechanics, and that bored me. But I loved mathematics. I would rather do mathematics than go to the movies in those days. But after a while, I discovered quantum mechanics, and that got me interested in physics again, and I've been hooked ever since."

After being awarded her Bachelor of Science degree in Mathematics in 1984, Hau continued to study at the University of Aarhus for her Master's degree in Physics which was awarded two years later. For her doctoral studies in quantum theory, Hau worked on ideas similar to those involved in fibre optic cables carrying light, but her work involved strings of atoms in a silicon crystal carrying electrons. While working towards her doctorate Hau spent seven months at CERN, the European Laboratory for Particle Physics near Geneva. In 1991 she was awarded a doctoral degree but before that her research had changed direction.

In 1988 she had received a Carlsberg Scholarship which enabled her to spend a year undertaking research: "I was lucky to be a Dane. Denmark has a long scientific tradition that included the great Niels Bohr, one of the founders of quantum theory. In Denmark, physics is widely respected by laymen as well as scientists, and laymen contribute to physics. For instance, research in quantum mechanics has been supported in Denmark by the makers of Carlsberg beer since the 1920's. I myself was supported as a graduate student for one year by a Carlsberg scholarship."

Career

In 1988 Lene Hau went to Harvard University in the United States and there she met Jene A. Golovchenko and discusses her future research ideas with him. He worked both at Harvard and at the Rowland Institute for Science in Cambridge, Massachusetts, which had been founded by the inventor of Polaroid photography, Edwin H. Land: "I told Jene what I had been doing and also that I wanted a complete change in direction. I wanted to work on cooling atoms. He told me he didn't know anything about cooling atoms but said we could work together on it, so I was given a post-doctoral appointment. Later, the Rowland Institute gave me a staff job and my own laboratory."

Her first year as a postdoctoral assistant was funded by the Carlsberg Scholarship but she was later appointed Gordon McKay Professor of Applied Physics at Harvard as well as Principal Investigator for the Atom Cooling Group at the Rowland Institute. A 1992 paper Bound states of guided matter waves: An atom and a charged wire described the work for which she had been awarded her doctorate.

Hau is famous, not for the work of her thesis but, rather, for her later experiments to slow down light. On February 18, 1999, the journal Nature selected for its cover article the paper Light speed reduction to 17 metres per second in an ultracold atomic gas written by Hau in collaboration with Stephen Harris of Stanford University and two Harvard graduate students Zachary Dutton and Cyrus Behroozi. Later work resulted in slowing light to about one mile per hour, then in 2001, her team were able to stop light for one-thousandth of a second. Hau said: "... this is an amazingly long time. But we think it can be stopped for much longer... It's nifty to look into the chamber and see a clump of ultracold atoms floating there. In this odd state, light takes on a more human dimension; you can almost touch it."

The way that this has been achieved involves rather a technical description. The first step was the creation of the "candlestick" by Hau and Golovchenko in 1994. This is a: "... device [which] wicks sodium atoms out of molten sodium metal and projects them into a cooling apparatus that, by using lasers, cools the atoms to a temperature 50 billionths of a degree above absolute zero."

For the experiment to slow light the "candlestick" is used to cool sodium atoms to 50 billionths of a degree above absolute zero. They are then trapped in a magnet and cooled still further by evaporation; a Bose-Einstein condensate containing millions of atoms results. Such a condensate was predicted by Satyendranath Bose and Einstein in 1924 but it was not until 1994 that the technology was available to produce temperatures low enough to create a condensate in an experiment. Although the condensate contains millions of atoms it behaves as if it were a single atom, but still exhibiting the usual particle wave duality. The reason for the behavior of the Bose-Einstein condensate is essentially due to the Heisenberg Uncertainty Principle for at such low temperatures the momentum of the atoms is known accurately so their positions cannot be accurately known so, in some sense, spread out. Hau produced slow light by inducing quantum interference in the condensate.

Many advances are expected to result from these stunning experiments such as discovering the fundamental properties of Bose-Einstein condensates. Other advances which may result could revolutionize telecommunications and computers with advances such as producing optical switches that are operated by a single photon.

Hau is now Mallinckrodt Professor of Physics and Applied Physics at Harvard. She has received many honors for her work including the Year 2000 Award from the Top Danmark Foundation, Copenhagen (2000); the Samuel Friedman Award from the Friedman Foundation, University of California (2001); the Ole Romer Medal from the University of Copenhagen (2001); the NKT Award from the Danish Physical Society (2001); and an honorary degree from the University of Copenhagen (2001). She was also awarded the Richtmyer Memorial Lecture Award from the American Association of Physics Teachers (2003) for "... dedication to teaching and research [and her] ability to give an exciting and informative lecture" and the Ledlie Prize from Harvard University (September 2008).

Hau was a MacArthur Fellow from 2001 to 2006 and was selected by the MacArthur Foundation as one of only nine MacArthur Fellows to be featured in connection with the 25th anniversary of the MacArthur Fellows programme. The nine fellows were selected from among all MacArthur fellows named over the history of the fellows' programme. She was elected to the Royal Swedish Academy of Sciences on January 16, 2008, and elected to the American Academy of Arts and Sciences on April 20, 2009. In addition to these and other awards, in 2007 Hau and her team were selected by Nature as the "Favourite of 2007 in Quantum Physics" and her team was also selected by the American Institute of Physics as "Top Ten Physics News Stories of 2007."

Achievements

• Lene Vestergaard Hau is a widely known Danish physicist who entered the annals of science history in 2001 when she and her team of researchers at Harvard University became the first to physically halt the speed of light. Later that year, Hau was awarded one of the MacArthur Foundation "genius" grants for her accomplishment.
  
  Hau has received many honors for her work including the Year 2000 Award from the Top Danmark Foundation, Copenhagen; the Ole Romer Medal from the University of Copenhagen; the Richtmyer Memorial Lecture Award from the American Association of Physics Teachers for "... dedication to teaching and research [and her] ability to give an exciting and informative lecture" and the Ledlie Prize from Harvard University.

Works

• book

  • Optics With Cold Atoms 2004
  • Methods, systems, and apparatus for storage, transfer and/or control of information via matter wave dynamics 2012

Politics

Lene Vestergaard Hau isn't involved in politics.

Views

Hau and her associates at Harvard University "have demonstrated exquisite control over light and matter in several experiments, but her experiment with 2 condensates is one of the most compelling". In 2006 they successfully transferred a qubit from light to a matter wave and back into light, again using Bose-Einstein condensates. Details of the experiment are discussed in the February 8, 2007 publication of the journal Nature. The experiment relies on the way that, according to quantum mechanics, atoms may behave as waves as well as particles. This enables atoms to do some counterintuitive things, such as passing through two openings at once. Within a Bose-Einstein condensate, a light pulse is compressed by a factor of 50 million, without losing any of the information stored within it. In this Bose-Einstein condensate, information encoded in a light pulse can be transferred to the atom waves. Because all the atoms move coherently, the information does not dissolve into random noise. The light drives some of the cloud's roughly 1.8 million sodium atoms to enter into "quantum superposition" states, with a lower-energy component that stays put and a higher-energy component that travels between the two clouds. A second "control" laser then writes the shape of the pulse into the atom waves. When this control beam is turned off and the light pulse disappears, the "matter copy" remains. Prior to this, researchers could not readily control optical information during its journey, except to amplify the signal to avoid fading. This experiment by Hau and her colleagues marked the first successful manipulation of coherent optical information. The new study is "a beautiful demonstration", says Irina Novikova, a physicist at the College of William and Mary in Williamsburg, VA. Before this result, she says, light storage was measured in milliseconds. "Here it's fractional seconds. It's a really dramatic time."

Of its potential, Hau said "While the matter is traveling between the two Bose-Einstein condensates, one can trap it, potentially for minutes, and reshape it - change it - in whatever way. This novel form of quantum control could also have applications in the developing fields of quantum information processing and quantum cryptography."

In 2009 Hau and team laser-cooled clouds of one million rubidium atoms to just a fraction of a degree above absolute zero. They then launched this millimeter-long atomic cloud towards a suspended carbon nanotube, located some two centimeters away and charged to hundreds of volts. The results were published in 2010, heralding new interactions between cold atoms and nanoscale systems. They observed that most atoms passed by, but approximately 10 per million were inescapably attracted, causing them to dramatically accelerate both in movement and in temperature. "At this point, the speeding atoms separate into an electron and an ion rotating in parallel around the nanowire, completing each orbit in just a few trillionths of a second. The electron eventually gets sucked into the nanotube via quantum tunneling, causing its companion ion to shoot away - repelled by the strong charge of the 300-volt nanotube - at a speed of roughly 26 kilometers per second, or 59,000 miles per hour." Atoms can rapidly disintegrate, without having to collide with each other in this experiment. The team is quick to note that this effect is not produced by gravity, as calculated in blackholes that exist in space, but by the high electrical charge in the nanotube. The experiment combines nanotechnology with cold atoms to demonstrate a new type of high-resolution, single-atom, chip-integrated detector that may ultimately be able to resolve fringes from the interference of matter waves. The scientists also foresee a range of single-atom, fundamental studies made possible by their setup.

Membership

• 

  Royal Danish Academy of Sciences and Letters

• 

  American Academy of Arts and Sciences

  2009

• 

  Foreign member

  Royal Swedish Academy of Sciences

  2008

Personality

Lene Vestergaard Hau likes to keep her personal life secret. She is also not very active on social media as she thinks it is a waste of time and she prioritizes her time to do more work in science.

Connections

Lene Hau is a married woman although not much is known about her personal life.

colleague:

Stephen Harris

Stephen Ernest Harris is an American physicist known for his contributions to electromagnetically induced transparency, modulation of single photons, and x-ray emission.

References

• Lene Vestergaard Hau on Facebook