[above:] We have observed quantum-limited spin transport in strongly interacting two-dimensional Fermi gases. We measure the rate of demagnetization of polarized samples in the presence of a magnetic field gradient, which drives coherence-eroding spin currents. We found that a lower bound on spin diffusivity, of roughly hbar/m, is respected for all interaction strengths, temperatures, and applied gradients accessible in our setup. See Luciuk et al., PRL 118, 130405 (2017).
[above:] We demonstrate fluorescence microscopy of individual fermionic potassium atoms in a 527-nm-period optical lattice. Using electromagnetically induced transparency (EIT) cooling on the 770.1-nm D1 transition of 40K, we find that atoms remain at individual sites of a 0.3-mK-deep lattice, with a 1/e pinning lifetime of 67(9)s, while scattering ~1000 photons per second. The plane to be imaged is isolated using microwave spectroscopy in a magnetic field gradient, and can be chosen at any depth within the three-dimensional lattice. With a similar protocol, we also demonstrate patterned selection within a single lattice plane. High resolution images are acquired using a microscope objective with 0.8 numerical aperture, from which we determine the occupation of lattice sites in the imaging plane with 94(2)% fidelity per atom. Imaging with single-atom sensitivity and addressing with single-site accuracy are key steps towards the search for unconventional superfluidity of fermions in optical lattices, the initialization and characterization of transport and non-equilibrium dynamics, and the observation of magnetic domains. More experimental details may be found in Edge et al., Phys. Rev. A 92, 063406 .
[above:] Observation of two new physical quantities, the p-wave contacts, via time-resolved spectroscopy. We study how correlations in our system develop after "quenching" the atoms into a state with near resonant p-wave interactions. The contacts appear as a unique frequency scaling in the spectra. These observations suggest a new way to characterize any gas with short-ranged p-wave interactions. More experimental details can be found in Luciuk et al., Nat. Phys. (2016) with a detailed theoretical treatment Yu et al., PRL 115, 135304 (2015).
[above:] Our recent paper on spin transport in a strongly interacting Fermi gas investigates how transverse spin currents are twisted by the spins that are responsible for their generation (a). We measure the Leggett-Rice parameter gamma that characterizes this precession (b), as well as the transverse spin diffusivity (c), as a function of temperature and interaction parameter kFa. More details can be found in Trotzky et al., PRL 114, 015301 (2015).
[above:] Spin Transport at the Planck Limit in a unitary Fermi gas. Using a spin echo, we measure the transverse demagnetization dynamics of a Fermi gas at a scattering resonance. We find that the magnetization dynamics are diffusive, described with a transverse spin diffusion constant Ds, whose value saturates to hbar/m at low tempeature.
More details can be found in Bardon et al., Science 344, 722 (2014).
26.May.2017: Peihang passes qualifying exam!
25.May.2017: Chris passes departmental PhD exam!
03.Apr.2017: Tristan Gauti arrives for a summer internship. Welcome!
31.Mar.2017: 2D spin transport paper appears in PRL.
15.Dec.2016: Graham Edge passes final Ph.D. defence! Next up: postdoc in the Vutha group.
05.Dec.2016: Preprint available describing our observations of quantum-limited spin transport in 2D Fermi gases.
Sept.2016:Ben Olsen and Fudong Wang arrive and join the lab as new post-docs. Welcome!
Sept.2016: Vijin passes MSc exam!
22.Aug.2016: Joseph presenting at Quantum Gases 2016 in Beijing.
11.July.2016: Geyue (Frank) Cai arrives from HKUST for a 10-week internship
2015-16: Five group alum have recently started faculty positions: Brian Shuve (at Harvey Mudd), Swati Singh (at Williams), David Shirokoff (at NJIT), John Simpson (at Waterloo), and Hyun Youk (at TU Delft). Congratulations all !
08.June.2016: Joseph presenting p-wave results at EQM2016 in St. Andrews, Scotland
24-27.May.2016: Group gives three talks and two posters at DAMOP in Providence RI
4.Apr.2016:Masahito Ueda writes Fermi gases: anisotropic universality in Nature News & Views, on our p-wave contact observation.
29.Feb.2016: Fabian Böttcher arrives from Stuttgart for a 3-month visit
22.Feb.2016: Our p-wave contact discovery appears online in Nature Physics!
11.Dec.2015: Fermi gas microscopes chosen as one of the Physics World top ten breakthroughs of 2015
8.Dec.2015: Fermi gas microscope paper chosen as ``Editor's Suggestion'' in PRA
15.Oct.2015: Preprint available on our imaging of individual fermionic atoms in an optical lattice
Sept.2015: Marcius joins XPRIZE as Director of Technical Operations for the Carbon XPRIZE
5-11.Sep.2015: Joseph presenting at the BEC conference in Sant Feliu, Spain
Sep.2015: Vijin, Peihang, and Haille join the group. Welcome!
18.Aug.2015: Rhys passes qualifying exam
17.Aug.2015: p-wave theory paper accepted to PRL
6.Aug.2015: Daniel passes M.Sc exam!
14-19.Jun.2015: Joseph presenting at Gordon conference
8-12.Jun.2015: Joseph, Rhys, and Chris presenting at DAMOP in Columbus
June.2015: Alma joins Morgan Solar, Inc. !
Apr.2015: Graham presenting at YAO in Zurich
Jan.2015: David McKay starts Research Staff position at IBM Watson Labs. Congratulations!
9.Mar.2015: First images of individual 40K atoms in a lattice!
16.Dec.2014: Scott passes M.Sc. exam!
5.Dec.2014: Leggett-Rice paper accepted to PRL!
30.Oct.2014:Preprint available on our observation of the Leggett-Rice effect in a unitary Fermi gas
Oct.2014: Nicolas Zuber arrives from Stuttgart for an 18-week research training visit
Aug.2014: Ryan becomes "Master Day"
Jul.2014: Dylan starts new job at Aerodyne Research; Alma starts postdoc at Sunnybrook.
16.Jun.2014: Dylan defends Ph.D. Congratulations!
22.May.2014: Alma defends Ph.D. Congratulations!
16.May.2014: Our article out in Science!
6.May.2014: Chris passes qualifying exam: now ABD...all-but-dissertation.
Mar.2014: Scott Beattie accepts position at NRC in Ottawa. Congratulations!
Oct.2013: Chris Veit & Matthias Wenzel arrive from Stuttgart for an 18-week research training visit. Just in time for the Fall foliage...
16-27.Sept.13: Ryan attends Les Houches PreDoc school in the French Alps!
Sept.2013: Rhys & Ryan join the lattice lab; Scott joins the chip lab.
5.Sept.2013: Chris earns M.Sc.!
23-28.Jun.13: Chris at Gordon Conference in Atomic Physics (Newport RI)
3-8.Jun.13: A busload of us going to DAMOP in Quebec City. Alma & Dylan presenting.
May.2013: Will Cairncross & Ryan Day start summer USRA positions.
Apr.2013: Lindsay is now Prof. LeBlanc: she accepts faculty position at U. Alberta!
2-5.Apr.13: Joseph at NewSpin3 in Mainz
Jan.2013: Dr. David McKay starts postdoc in the Schuster group at the University of Chicago.
[ ... see old news ...]