The development of quantum mechanics has been one of the most important achievements of modern physics. Quantum mechanics constitutes the basic foundation of nature on an atomic length scale. However, it is often at odds with our classical world, seemingly contradicting everyday experiences. In quantum mechanics, certainties are replaced by probabilities and a single atom, for example, can be in different states or even at different positions at a given time. Furthermore, quantum mechanics poses fundamental limits: We cannot know an object’s position and momentum at the same time. For nearly a century, it has been a dream of physicists to realize a macroscopic object that behaves purely quantum mechanically. A Bose-Einstein condensate (BEC) is exactly this – its realization gives physicists direct access to the quantum mechanical world.
The first BECs in ultracold atomic gases were realized by Eric Cornell and Carl Wieman at JILA/University of Colorado, and by Wolfgang Ketterle, MIT, in 1995 (see ). These three researchers were awarded the Nobel Prize in 2001. Since then the field of ultracold quantum gases (BECs and degenerate Fermi gases (DFGs)) has revolutionized modern physics and has developed into an extremely active and rapidly advancing research area. But even with today’s technologies, achieving a BEC or a DFG is no easy task. A cloud of atoms needs to be cooled to ultracold temperatures, just a few billionths of a degree above absolute zero. These are about the coldest temperatures ever realized, far colder than any naturally occurring temperature in the universe. Only with the development of powerful laser-cooling  and atom-trapping techniques has it become possible to venture into these extremely cold regimes.
C. Hamner, Yongping Zhang, M. A. Khamehchi, Matthew J. Davis, P. Engels, Spin-orbit coupled Bose-Einstein condensates in a one-dimensional optical lattice, arXiv version here.
Chris Hamner, Chunlei Qu, Yongping Zhang, JiaJia Chang, Ming Gong, Chuanwei Zhang, Peter Engels, Dicke-type phase transition in a spin-orbit coupled Bose-Einstein condensate, Nature Communications 5, 4023 (2014), arXiv version here.
C. Hamner, Yongping Zhang, J.J. Chang, Chuanwei Zhang, P. Engels, Phase Winding a Two-Component BEC in an Elongated Trap: Experimental Observation of Moving Magnetic Orders and Dark-bright Solitons, Phys. Rev. Lett 111264101 (2013) , arXiv version here.
Chunlei Qu, Chris Hamner, Ming Gong, Chuanwei Zhang, and Peter Engels, Observation of Zitterbewegung in a spin-orbit-coupled Bose-Einstein condensate, Phys. Rev. A 88, 021604 (2013) , arXiv version here.
A. Alvarez, J. Cuevas, F.R. Romero, C. Hamner, J.J. Chang, P. Engels, P.G. Kevrekidis and D.J. Frantzeskakis, Scattering of atomic dark-bright solitons from narrow impurities, J. Phys. B: At. Mol. Opt. Phys. 46, 065302 (2013), arXiv versionhere.
D. Yan, J.J. Chang, C. Hamner, M. Hoefer, P.G. Kevrekidis, P. Engels, V. Achilleos, D.J. Frantzeskakis and J. Cuevas, Beating dark-dark solitons in Bose-Einstein condensates, J. Phys. B: At. Mol. Opt. Phys., 45 115301 (2012)
doi:10.1088/0953-4075/45/11/115301, arXiv version here.
D. Yan, J.J. Chang, C. Hamner, P.G. Kevrekidis, P. Engels, V. Achilleos, D. J. Frantzeskakis, R. Carretero-Gonzalez, P. Schmelcher, Multiple dark-bright solitons in atomic Bose-Einstein condensates, Phys. Rev. A 84, 053630 (2011) , arXiv version here.
S. Middelkamp, J.J. Chang, C. Hamner, R. Carretero-Gonzalez, P.G. Kevrekidis, V. Achilleos, D.J. Frantzeskakis, P. Schmelcher, P. Engels, Dynamics of dark-bright solitons in cigar-shaped Bose-Einstein condensates, Physics Letters A 375, 642 (2011), arXiv version here.
M.A. Hoefer, J.J. Chang, C. Hamner, and P. Engels, Dark-dark solitons and modulational instability in miscible two-component Bose-Einstein condensates, Phys. Rev. A 84, 041605 (2011), arXiv version here.
P. Engels, Observing the dance of a vortex-antivortex pair, step by step,
Professor of Physics
Office: Webster Physical Sciences 654
Phone: (509) 335-4674
Fax: (509) 335-7816
E-mail: engels at wsu.edu
Research: Bose-Einstein Condensates