Quantum in motion

A relatively new and growing field of physics--the dynamics of non-equilibrium quantum systems--drew a diverse group of participants to Trieste on 21 June. For five days, scientists from 33 countries and six continents attended the "Dynamics of Strongly Correlated Quantum Systems" workshop.

Strongly correlated quantum systems are systems of interacting particles that have unusual collective behaviors. The field has potential applications in quantum optics, cold atomic gases, and quantum computing. Other applications include nanofabrication and transport on the nanoscale.

"The games we used to play in theory are now possible in experiment," says Alessandro Silva, an organiser of the conference and a visiting scientist with ICTP's Condensed Matter and Statistical Physics  (CMSP) section.  Advances in theoretical understanding, in-depth simulations, and experimental breakthroughs have boosted the field considerably. Silva describes the developments in the field during the past 10 years as the "dream of a theoretician."

"We had a lot of young people...this means that the field has a future," Silva says. He adds that he was astonished that 105 people attended for the relatively short workshop, and at the level of discussions that took place during free hours.  This year's workshop complements the more general three-week course in non-equilibrium physics that the CMSP group organized last summer.

One of the presenters, Marcos Rigol of Georgetown University, United States, spoke on "Quantum chaos and thermalization in finite one-dimensional systems". He explained his work on using quantum quenches to study the dynamics and thermalization of bosons: "You have some hot coffee and you pour in some cold milk just to cool it down. What happens if you pour the quantum soup of coffee into the quantum soup of milk?" Rigol's research also indicates that the definition of chaos is much the same in classical and quantum theories. "Things cannot be true in one of them and not true in the other. We have to match them."

For presenter Vladimir Gritsev of the University of Fribourg, Switzerland, the conference was his fifth trip to ICTP in the past two years.  He feels that we could be witnessing a paradigm shift and that the field is "currently at the point of creating a general language" for the diverse group of participants that includes theoreticians and experimentalists.

Silva hopes that the conference was well timed to give the people starting out in the field added momentum. The organizers are already finalizing next year's instalment in the series of workshops.

More details about the workshop can be found here.