title: Spin-injection spectroscopy of a spin-orbit coupled Fermi gas.
abstract: The coupling of the spin of electrons to their motional state lies at the heart of recently discovered topological phases of matter. Here we create and detect spin-orbit coupling in an atomic Fermi gas, a highly controllable form of quantum degenerate matter. We directly reveal the spin-orbit gap via spin-injection spectroscopy, which characterizes the energy-momentum dispersion and spin composition of the quantum states. For energies within the spin-orbit gap, the system acts as a spin diode. We also create a spin-orbit coupled lattice and probe its spinful band structure, which features additional spin gaps and a fully gapped spectrum. In the presence of s-wave interactions, such systems should display induced p-wave pairing, topological superfluidity, and Majorana edge states.
authors.affiliation: Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA.
authors.forename: Lawrence W
authors.initials: LW
authors.lastname: Cheuk
authors.forename: Ariel T
authors.initials: AT
authors.lastname: Sommer
authors.forename: Zoran
authors.initials: Z
authors.lastname: Hadzibabic
authors.forename: Tarik
authors.initials: T
authors.lastname: Yefsah
authors.forename: Waseem S
authors.initials: WS
authors.lastname: Bakr
authors.forename: Martin W
authors.initials: MW
authors.lastname: Zwierlein