TU Vienna - With the awarding of the START prize in October 2009, Schumm embarked upon a great journey, and with the awarding of the ERC Starting Grant he has now taken a further step towards his goal of building a nuclear atomic clock. Since the beginning of the START project in January 2010, Thorsten Schumm has built up a research team - together with his colleagues Georg Steinhauser (Postdoc), Georg Winkler (PhD) and Michael Schreitl (PhD) - to drive the project forwards at the Institute of Atomic and Subatomic Physics.

How accurate is the clock?

The radio-isotope ²²⁹thorium is the only atom which can bridge the gap between the previously completely separate worlds of atomic and nuclear physics. The excitation state of its atomic nucleus has such exceptionally low energy that the methods of atomic physics, in particular spectroscopy with lasers, can be employed. The goal of the project is to demonstrate this "optical" nuclear transition and make it useable for applications and fundamental physics research.

At present, we define a "second" as 9,192,631,770 oscillations of a light wave, which causes a specific excitation of the electron shell of a caesium atom. However, excitations of the electron shell are very sensitive to magnetic and electric fields, which means that the atoms in atomic clocks require sophisticated shielding. In addition, the measurements must be carried out in ballistic (free) fall. Further improvement of the conventional atomic clock concept therefore requires satellite-supported superstructures. If the optical ²²⁹thorium nuclear transition could be used, the accuracy of our time standards could be significantly increased, while at the same time the sophistication of the apparatus could be greatly simplified, as neither shielding nor ballistic measurements would be necessary. The aim of this project is to develop such a nuclear atomic clock.

Unique research environment at the Vienna University of Technology

As part of the renovation work at the Institute of Atomic and Subatomic Physics, a very special new laboratory is currently being purpose-built for this project. This laboratory meets the very highest laser operation requirements (extremely stable temperatures, low levels of vibration) and also has radiation protection approval and the appropriate equipment. "This environment is truly unique and demonstrates TU Vienna's commitment to this project," explains Schumm enthusiastically. The laboratory is due to be completed by October 2010. In general, the combination of nuclear and particle physics with precision laser spectroscopy is very rare and the Institute of Atomic and Subatomic Physics at TU Vienna is one of the very few places in the world where this is possible.

About Thorsten Schumm

Born in Berlin in 1975, Schumm now boasts an extremely impressive CV: He studied Mechanical Engineering (1995-1996, TU Berlin) and then Physics and Philosophy (1996-2002 FU Berlin) and finally attained a Diploma in Experimental Physics ("with distinction") at the universities of Innsbruck and Heidelberg (2000-2002). From 2003 to 2005, Schumm added to his achievements with a European Double Doctorate (Cotutelle de thèse) from the Université Paris Sud and the University of Heidelberg (summa cum laude, "très honorable").
Professional career: Since 2006, Thorsten Schumm has been an Assistant Researcher at the Institute of Atomic and Subatomic Physics at the Vienna University of Technology, and since 2008 he has been a member and programme director at the Wolfgang Pauli Institute. In 2006, he worked as a postdoc at the McLennan Physical Laboratories at the University of Toronto.

International network

The project is now supported by strong international collaboration, both in Europe and the USA. The project partners include:

• Federal Institute of Physics and Technology (PTB), Braunschweig
• Fraunhofer Institute for Integrated Systems and Components (IISB), Erlangen
• Institute for Crystal Growth (IKZ), Berlin
• Max-Born Institute for Non-linear Optics and Short-Pulse Spectroscopy, Berlin
• Keele University, England
• University of California, Los Angeles, US

Internet links

http://www.thorium.at, opens an external URL in a new window (project website)
http://www.ati.ac.at, opens an external URL in a new window (Institute of Atomic and Subatomic Physics)
http://erc.europa.eu, opens an external URL in a new window (European Research Council)

For more information please contact

Dr Thorsten Schumm
Vienna University of Technology
Institute of Atomic and Subatomic Physics
Stadionallee 2, 1020 Vienna, Austria
Phone: +43 1 58801  541 72
Email: thorsten.schumm@tuwien.ac.at
Email: schumm@thorium.at