At extremely low temperatures atoms can aggregate into so-called Bose Einstein condensates forming coherent laser-like matter waves. Due to interactions between the atoms fundamental quantum dynamics emerge and give rise to periodic collapses and revivals of the matter wave field. We have now now succeeded to take a glance ‘behind the scenes’ of atomic interactions revealing the complex structure of these quantum dynamics. By generating thousands of miniature BECs ordered in an optical lattice we were able to observe a large number of collapse and revival cycles over long periods of time. Our experimental results imply that the atoms do not only interact pairwise - as typically assumed - but also perform exotic collisions involving three, four or more atoms at the same time. On the one hand, these results have fundamental importance for the understanding of quantum many-body systems. On the other hand, they pave the way for the generation of new exotic states of matter, based on such multi-body interactions.

Press Release by Max-Planck Institute of Quantum Optics:

( deu | eng )

Sebastian Will, Thorsten Best, Ulrich Schneider, Lucia Hackermüller, Dirk-Sören Lühmann, and Immanuel Bloch

„Time-resolved observation of coherent multi-body interactions in quantum phase revivals“

Nature, 465, 197-201 (2010)

Yedidyah Dordek from Technion Institute of Technology in Haifa has prepared a Hebrew version of my 2004 seminar paper on quantum teleportation. I‘m really impressed :-)

Download here: ( hebrew | eng )

MAY 13, 2010

Quantum Dynamics of Matter Waves reveal exotic Multi-Body Collisions

JUNE 13, 2010

Hebrew Version of my Seminar Paper on Quantum Teleportation!

The individual sites of an optical lattice can be regarded as micro-laboratories to study the behavior of interacting atoms with exceptional precision. We have prepared an elementary impurity system on the sites of an optical lattice consisting of a single fermionic atom and a miniature Bose-Einstein condensate. With the newly developed technique of quantum phase revival spectroscopy it was possible to study the interactions in this system with a breathtaking precision: For the first time, we could directly reveal, that the presence of an interacting impurity also changes the interactions between the majority population atoms.

Sebastian Will, Thorsten Best, Simon Braun, Ulrich Schneider, and Immanuel Bloch

„Coherent Interaction of a Single Fermion with a Small Bosonic Field“

Physical Review Letters 106, 115305 (2011) or arXiv:1011.3807

MARCH 18, 2011

Coherent Interaction between a Single Fermion and a Small Bosonic Field

In this work we demonstrate that quantum phase revival dynamics can be used to create exotic condensate states, which show regular patterns in momentum space as opposed to populating only a single momentum component.

The observation of such phenomena becomes possible, when quantum phase revival dynamics is performed in a strong harmonic confinement.

Michael Buchhold, Ulf Bissbort, Sebastian Will, and Walter Hofstetter

„Creating Exotic Condensates Through the Interplay of Quantum Phase Revival and Trap Dynamics“

See: arXiv:1012.5100

DECEMBER 24, 2010

Creating Exotic Condensates Through the Interplay of Quantum Phase Revival and Trap Dynamics

NOVEMBER 10, 2011

Successful defense of my PhD thesis!

Today I successfully defended my thesis „Interacting bosons and fermions in three-dimensional optical lattice potentials - From atom optics to quantum simulation“ at the University of Mainz with summa cum laude :)

My colleagues at LMU Munich have built a wonderful doctoral hat („Doktorhut“) for me. It has been so moving. Thank you so much, guys!

The orange LED show on top of the hat imitates the collapse and revival quantum dynamics of bosonic atoms in an optical lattice (see the bottom of this page). It is absolutely fantastic!