Quantum materials research with ultra-cold atoms and molecules

Overview of research themes and direction : experimental quantum field theory

Since the advent of laser cooling and trapping, researchers have been using ultra-cold atomic samples for the study of various fundamental physical phenomena in the domains of quantum optics, quantum transport and quantum chaos. With the more recent achievement of Bose-Einstein condensation and degenerate Fermi gases, many-body quantum systems have become a subject of intense investigation for researchers in this field. My area of research is in the application of ultra-cold atomic gases to the study of strongly correlated quantum ensembles where, because of interactions, the states of the system can develop correlations and novel behaviors beyond the scope of mean field and independent particle descriptions. The main emphasis of this research is on strongly correlated systems of particular interest and relevance to the condensed matter community.

One of the primary goals is to bridge the fundamental gap which remains between materials experiments on and the theoretical description of high-Tc superconductivity. By putting an ultra-cold gas of fermionic atoms into an optical crystal or optical lattice formed by the interference pattern of intersecting laser beams, one can realize a physical system capable of behaving like the system of electrons (also fermions) flowing in a superconducting crystal. Using this system, we hope to determine the essential conditions under which superconductivity persists at high temperatures. Approaching this and other long standing mysteries of condensed matter physics with this new experimental quantum system may provide additional information crucial to their final unraveling.

The application of ultra-cold atomic gases to the study of many-body systems is presently an area of explosive growth with relevance to quantum information technologies, quantum simulators and quantum computation, and fundamental condensed matter physics. Because of the freedom to introduce and control both the external potentials and inter-particle interactions as well as the almost perfect isolation from the environment, these systems are ideal for the realization and study of many model Hamiltonians. Moreover, in addition to providing a completely novel approach for the study of the long standing mysteries associated with high-Tc superconductivity, these atomic gases also provide an inspiring tool capable of creating completely new and unexplored experimental systems whose realization and study will no doubt reveal exotic and unanticipated phenomena further enriching and advancing the frontiers of quantum materials and condensed matter physics.

We are pursuing the experimental observation of both few and many-body quantum effects using cold atoms and cold molecules formed from cold atoms. Our goals include:
  • controlling cold collisions between Rb and Li atoms using both external magnetic and electric fields.
  • the use of optically tuned atom-atom interactions to study dynamics of strongly interacting fermi gases and bose-fermi mixtures
  • the formation and study of quantum degenerate gases of deeply bound Rb2 Li2 and Rb-Li dimers

Associated publications

Gene Polovy, Erik Frieling, Denis Uhland, Julian Schmidt, and Kirk W. Madison
Quantum-state-dependent chemistry of ultracold Li2 dimers
Phys. Rev. A 102, 013310 (2020)

Gene Polovy, Julian Schmidt, Denis Uhland, Erik Frieling, Kahan Dare, and Kirk W. Madison
Phase noise reduction of mutually tunable lasers with an external acousto-optic modulator
JOSA B, Vol. 36, Issue 2, pp. 464-469 (2019)

William Bowden, Will Gunton, Mariusz Semczuk, Kahan Dare, and Kirk W. Madison
Dual Species Effusive Source and Zeeman Slower for Cold Atom Experiments
Rev. Sci. Instrum. 87, 043111 (2016) || http://arxiv.org/abs/1509.07460

Will Gunton, Gene Polovy, Mariusz Semczuk, Kirk W. Madison
Transparent Electrodes for High E-Field Production Using A Buried ITO Layer
Rev. Sci. Instrum. 87, 033113 (2016) || http://arxiv.org/abs/1508.04086

Will Gunton, Mariusz Semczuk, and Kirk W. Madison
A method for independent and continuous tuning of N lasers phase-locked to the same frequency comb
Optics Letters, vol. 40, pp. 4372-4375 (2015) || http://arxiv.org/abs/1506.00389

Mariusz Semczuk, Will Gunton, William Bowden, and Kirk W. Madison
Anomalous Behavior of Dark States in Quantum Gases of Li6
Phys. Rev. Lett. 113, 055302 (2014) || http://arxiv.org/abs/1407.7904 || local copy

Will Gunton, Mariusz Semczuk, Nikesh S. Dattani, and Kirk W. Madison,
High resolution photoassociation spectroscopy of the 6Li_2 A(1^1\Sigma_u^+) state,
Phys. Rev. A 88, 062510 (2013) || http://arxiv.org/abs/1309.5870

Michal Tomza, Kirk W. Madison, Robert Moszynski, Roman V. Krems
Chemical reactions of ultracold alkali dimers in the lowest-energy $^3\Sigma$ state
Phys. Rev. A 88, 050701(R) (2013) || http://arxiv.org/abs/1308.4783

Will Gunton, Mariusz Semczuk, and Kirk W. Madison,
Realization of BEC-BCS crossover physics in a compact oven-loaded magneto-optic trap apparatus
Phys. Rev. A 88, 023624 (2013) || arXiv:1307.5445

Mariusz Semczuk, Xuan Li, Will Gunton, Magnus Haw, Nikesh S. Dattani, Julien Witz, Arthur Mills, David J. Jones, and Kirk W. Madison,
High resolution photoassociation spectroscopy of the 6Li_2 1^{3}\Sigma_{g}^{+} state,
Phys. Rev. A 87, 052505 (2013) || http://arxiv.org/abs/1309.6662

Felipe Herrera, Kirk W. Madison, Roman V. Krems, Mona Berciu,
Investigating polaron phase transitions with polar molecules,
Phys. Rev. Lett. 110, 223002 (2013) || http://arxiv.org/abs/1212.6212

B. Deh, W. Gunton, B. G. Klappauf, Z. Li, M. Semczuk, J. Van Dongen, and K. W. Madison
Giant Feshbach resonances in 6Li-85Rb mixtures
Phys. Rev. A 82, 020701(R) (2010)

Z. Li and K.W. Madison,
Effects of Electric Fields on Heteronuclear Feshbach Resonances in Ultracold 6Li-87Rb Mixtures,
Phys. Rev. A 79, 042711 (2009) || arXiv:0902.2505

A. K. Mills, Y.-F. Chen, K. W. Madison, and D. J. Jones,
A widely tunable, single frequency optical frequency synthesizer with a 100 kHz uncertainty,
J. Opt. Soc. Am. B 26, 1276-1280 (2009)

K. Ladouceur, B.G. Klappauf, J. Van Dongen, N. Rauhut, B. Schuster, A.K. Mills, D.J. Jones, and K.W. Madison,
Compact laser cooling apparatus for simultaneous cooling of lithium and rubidium,
J. Opt. Soc. Am. B 26, 210-217 (2009)

Z. Li, S. Singh, T. V. Tscherbul, K. W. Madison,
Feshbach resonances in ultracold 85Rb-87Rb and 6Li-87Rb mixtures,
Phys. Rev. A 78, 022710 (2008) || September 2008 issue of Virtual Journal of Quantum Information|| http://arxiv.org/abs/0807.0417

A. K. Mills, Y.-F. Chen, J. Jiang, K. W. Madison, and D. J. Jones,
Using Difference Frequency Generation to Lock a CW Visible Laser to a Fiber Laser Frequency Comb,
Proceedings of Quantum Electronics and Laser Science Conference and Photonic Ap\ plications Systems Technologies,
Optical Society of America, Technical Digest (CD), (2008), paper CFA4.




A 6Li MOT with N ~ 10^8 atoms at T < 1mK.




Atoms are transferred from the MOT to an optical dipole trap where forced evporative cooling is used to lower the temperature even more.
Pictured are absorption images of lithium atoms and Feshbach (halo) dimers of lithium in an optical dipole trap