title: Orbital Feshbach Resonance in Alkali-Earth Atoms.
abstract: For a mixture of alkali-earth atomic gas in the long-lived excited state ^{3}P_{0} and the ground state ^{1}S_{0}, in addition to nuclear spin, another "orbital" index is introduced to distinguish these two internal states. In this Letter we propose a mechanism to induce Feshbach resonance between two atoms with different orbital and nuclear spin quantum numbers. Two essential ingredients are the interorbital spin-exchange process and orbital dependence of the Landé g factors. Here the orbital degrees of freedom plays a similar role as the electron spin degree of freedom in magnetic Feshbach resonance in alkali-metal atoms. This resonance is particularly accessible for the ^{173}Yb system. The BCS-BEC crossover in this system requires two fermion pairing order parameters, and displays a significant difference compared to that in an alkali-metal system.
authors.affiliation: Institute for Advanced Study, Tsinghua University, Beijing 100084, China.
authors.forename: Ren
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Institute for Advanced Study, Tsinghua University, Beijing 100084, China.
authors.forename: Yanting
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Institute for Advanced Study, Tsinghua University, Beijing 100084, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhai
authors.affiliation: Department of Physics, Renmin University of China, Beijing 100872, China.|Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin Univeristy of China, Beijing 100872, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang