# Julia Kempe

**Quantum Mechanic
**

© J.-F. Dars/CNRS Photothèque

After a brief silence, Julia Kempe replies, “when you say my roots, do you mean by birth or by adoption?” But no answer is really necessary. It is obvious that at 33, this Berliner of Russian descent is wary of reductionist descriptions. This is illustrated by her scientific career, which took her across the world and, six years ago, into the stronghold of “quantum computing” experts in France, the LRI

^{1} in Orsay. And it was a successful move: In 2006, Kempe was awarded the CNRS bronze medal and the Irène Joliot-Curie award for “young female scientist of the year.” She recently left for Tel Aviv to continue her work in this leading-edge theoretical field. With her discreet and level-headed demeanor, Julia is in perpetual motion between two destinations and two fields of study. Working on quantum computing, a mathematical field that uses the laws of quantum mechanics to solve problems much faster than via traditional methods,

^{2} she has managed to successfully reconcile mathematics and physics.

She has been involved in math since childhood: Educated by the East German schooling system, she won the mathematical Olympics in her hometown. But the fall of the Berlin Wall changed everything. At 18 she was already in
Vienna working on a dual university degree. She then moved to Sydney to learn about the electromagnetic properties of groups of particles.

She finally settled down in Paris, pursuing her love of French literature and the certainty of finding famous mathematicians to work with. After receiving a post-graduate degree in theoretical physics, she discovered quantum computing–a brand new field at the time. Three years earlier, American research scientist Peter Shor had shown how a quantum algorithm could factor a number far more quickly than traditional algorithms. “You have to understand that a substantial part of cryptography was based on the assumption that no one could factor at high speed. After his discovery, it became obvious that one day, codes that protect credit cards, for example, would be broken,” adds Kempe. “This field combined everything I loved, and the hope to one day create a computer based on the principles of quantum mechanics. What could be more exciting?”

Her next stop was Berkeley, California, a mecca for this emerging field of research. But even in exile, Julia remained tied to France, “so much so that I was working on two theses at once–one in mathematics in California, and another in computer science in Paris.” Among other things, she has developed methods to facilitate noise correction on quantum data. In 2001, driven by her nostalgia for the Old Continent, she applied for a position at CNRS–which accepted her immediately. Since then, she has pursued research in several areas. One focuses on “adiabatic computing,” a promising and equivalent alternative to traditional quantum computing, as she and her colleagues have demonstrated. Another is “complexity theory”: identifying the advantages of quantum computing over its traditional equivalent. “It is quite hard for me to pinpoint the exact reasons why I returned to France. They include both the high level of the science, the extensive autonomy given to research scientists... and then, of course, there's the culture.”

Patricia Chairopoulos

### Notes :

1. Laboratoire de recherche en informatique (CNRS / Université Paris-XI).

2. For example, a quantum particle can be in several states “at once,” allowing exploration of several directions in parallel.