Abstract
Atomic spins are usually manipulated using radio frequency or microwave fields to excite Rabi oscillations between different spin states. These are single-particle quantum control techniques that perform ideally with individual particles or non-interacting ensembles. In many-body systems, inter-particle interactions are unavoidable; however, interactions can be used to realize new control schemes unique to interacting systems. Here we demonstrate a many-body control scheme to coherently excite and control the quantum spin states of an atomic Bose gas that realizes parametric excitation of many-body collective spin states by time varying the relative strength of the Zeeman and spin-dependent collisional interaction energies at multiples of the natural frequency of the system. Although parametric excitation of a classical system is ineffective from the ground state, we show that in our experiment, parametric excitation from the quantum ground state leads to the generation of quantum squeezed states.
Highlights
Atomic spins are usually manipulated using radio frequency or microwave fields to excite Rabi oscillations between different spin states
We show that the finite quantum fluctuations of the collective spin leads to parametric excitation of the ground state, which manifest as exponential evolution of the fluctuations and the generation of non-classical squeezed states
The experiments use 87Rb Bose condensates with N 1⁄4 40,000 atoms in the F 1⁄4 1 hyperfine level tightly confined in optical traps such that spin domain formation is energetically suppressed and dynamical evolution of the system occurs only in the internal spin variables
Summary
Atomic spins are usually manipulated using radio frequency or microwave fields to excite Rabi oscillations between different spin states. These are single-particle quantum control techniques that perform ideally with individual particles or non-interacting ensembles. We demonstrate a many-body control scheme to coherently excite and control the quantum spin states of an atomic Bose gas that realizes parametric excitation of many-body collective spin states by time varying the relative strength of the Zeeman and spin-dependent collisional interaction energies at multiples of the natural frequency of the system. We show that the finite quantum fluctuations of the collective spin leads to parametric excitation of the ground state, which manifest as exponential evolution of the fluctuations and the generation of non-classical squeezed states. We discuss how these techniques can be applied to related systems including the double-well Bose–Hubbard model and interacting (psuedo) spin-1/2 ensembles
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
