Abstract
We investigate the synthesis of a hyperfine spin lattice in an atomic Bose–Einstein condensate, with two hyperfine spin components, inside a one-dimensional high-finesse optical cavity, using off-resonant superradiant Raman scattering. Spatio-temporal evolution of the relative population of the hyperfine spin modes is examined numerically by solving the coupled cavity–condensate mean-field equations in the dispersive regime. We find, analytically and numerically, that beyond a certain threshold of the transverse laser pump, Raman superradiance and self-organization of the hyperfine spin components occur simultaneously and as a result a magnetic lattice is formed. The effects of an extra laser pump parallel to the cavity axis and the time dependence of the pump strength on the synthesis of a sharper lattice are also addressed.
Highlights
The controversy over the expectation value of the intrinsic ground-state angular momentum of the A phase of superfluid 3He in a given container has a long history, and it has not yet attained a universally agreed resolution [1]
We argue that the origin of spontaneously induced counterflowing mass currents in spin-orbit-coupled Fermi gases can be understood via a direct correspondence with chiral p-wave superfluids and superconductors, but with some fundamental differences
We find that the mass current flows as long as the spin-orbit coupling (SOC) field has both x and y components, and its strength decreases gradually as a function of increasing asymmetry of the SOC fields
Summary
The controversy over the expectation value of the intrinsic ground-state angular momentum of the A phase of superfluid 3He in a given container has a long history, and it has not yet attained a universally agreed resolution [1]. The former expectation, which is based on the observation that pairing affects not all but only a small fraction (| |/εF )N of fermions, seems more intuitive This subject has recently regained interest in the condensed-matter and atomic and molecular physics communities due to its relevance to the possible px + ipy superconducting phase of Sr2RuO4 [2] and atomic chiral p-wave superfluids [3], respectively, which support the latter expectation [4,5]. They seem counterintuitive in the weak-fermion-attraction limit of loosely bound and largely overlapping p-wave Cooper pairs, since these results imply that the angular momentum in the BCS ground state is macroscopically different from its vanishing value in the normal ground state, when the pairing energy becomes arbitrarily small While this controversy still awaits an experimental resolution, here we propose an alternative atomic system where the microscopic angular momentum of Cooper pairs can give rise to a macroscopic one. With their unique advantages over condensed-matter systems, it is plausible that the macroscopic angular momentum of this alternative system may be observed for the first time with cold atoms, and that this would shed some light on the 3He controversy for which the basic mechanism is found to be similar
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