TY - JOUR
AU - S. Kolkowitz
AU - Sarah Bromley
AU - Tobias Bothwell
AU - Michael Wall
AU - Edward Marti
AU - A. Koller
AU - X. Zhang
AU - Ana Maria Rey
AU - Jun Ye
AB - Engineered spin–orbit coupling (SOC) in cold-atom systems can enable the study of new synthetic materials and complex condensed matter phenomena1,2,3,4,5,6,7,8. However, spontaneous emission in alkali-atom spin–orbit-coupled systems is hindered by heating, limiting the observation of many-body effects1,2,5 and motivating research into potential alternatives9,10,11. Here we demonstrate that spin–orbit-coupled fermions can be engineered to occur naturally in a one-dimensional optical lattice clock12. In contrast to previous SOC experiments1,2,3,4,5,6,7,8,9,10,11, here the SOC is both generated and probed using a direct ultra-narrow optical clock transition between two electronic orbital states in 87Sr atoms. We use clock spectroscopy to prepare lattice band populations, internal electronic states and quasi-momenta, and to produce spin–orbit-coupled dynamics. The exceptionally long lifetime of the excited clock state (160 seconds) eliminates decoherence and atom loss from spontaneous emission at all relevant experimental timescales, allowing subsequent momentum- and spin-resolved in situ probing of the SOC band structure and eigenstates. We use these capabilities to study Bloch oscillations, spin–momentum locking and Van Hove singularities in the transition density of states. Our results lay the groundwork for using fermionic optical lattice clocks to probe new phases of matter.
BT - Nature
DA - 2017-02
DO - 10.1038/nature20811
N2 - Engineered spin–orbit coupling (SOC) in cold-atom systems can enable the study of new synthetic materials and complex condensed matter phenomena1,2,3,4,5,6,7,8. However, spontaneous emission in alkali-atom spin–orbit-coupled systems is hindered by heating, limiting the observation of many-body effects1,2,5 and motivating research into potential alternatives9,10,11. Here we demonstrate that spin–orbit-coupled fermions can be engineered to occur naturally in a one-dimensional optical lattice clock12. In contrast to previous SOC experiments1,2,3,4,5,6,7,8,9,10,11, here the SOC is both generated and probed using a direct ultra-narrow optical clock transition between two electronic orbital states in 87Sr atoms. We use clock spectroscopy to prepare lattice band populations, internal electronic states and quasi-momenta, and to produce spin–orbit-coupled dynamics. The exceptionally long lifetime of the excited clock state (160 seconds) eliminates decoherence and atom loss from spontaneous emission at all relevant experimental timescales, allowing subsequent momentum- and spin-resolved in situ probing of the SOC band structure and eigenstates. We use these capabilities to study Bloch oscillations, spin–momentum locking and Van Hove singularities in the transition density of states. Our results lay the groundwork for using fermionic optical lattice clocks to probe new phases of matter.
PY - 2017
SE - 66
EP - 66–70
T2 - Nature
TI - Spin-orbit-coupled fermions in an optical lattice clock
UR - http://www.nature.com/doifinder/10.1038/nature20811
VL - 542
SN - 0028-0836
ER -