Abstract
The strong light–matter coupling attainable in optical cavities enables the generation of highly squeezed states of atomic ensembles. It was shown by Sørensen and Mølmer (2002 Phys. Rev. A 66 022314) how an effective one-axis twisting Hamiltonian can be realized in a cavity setup. Here, we extend this work and show how an effective two-axis twisting Hamiltonian can be realized in a similar cavity setup. We compare the two schemes in order to characterize their advantages. In the absence of decoherence, the two-axis Hamiltonian leads to more squeezing than the one-axis Hamiltonian. If limited by decoherence from spontaneous emission and cavity decay, we find roughly the same level of squeezing for the two schemes scaling as where C is the single atom cooperativity and N is the total number of atoms. When compared to an ideal squeezing operation, we find that for specific initial states, a dissipative version of the one-axis scheme attains higher fidelity than the unitary one-axis scheme or the two-axis scheme. However, the unitary one-axis and two-axis schemes perform better for general initial states.
Highlights
Spin squeezed states of atomic ensembles have many applications as resources for quantum enhanced metrology [1,2,3,4,5], continuous variable quantum information processing [6], and multipartite entanglement [7,8,9]
A 66, 022314 (2002)] how an effective one-axis twisting Hamiltonian can be realized in a cavity setup
We extend this work and show how an effective two-axis twisting Hamiltonian can be realized in a similar cavity setup
Summary
Spin squeezed states of atomic ensembles have many applications as resources for quantum enhanced metrology [1,2,3,4,5], continuous variable quantum information processing [6], and multipartite entanglement [7,8,9]. In continuous variable quantum information processing applications [6] where the objective is to implement a squeezing operation on a generic input state, coherent schemes [11, 12, 22,23,24] may be advantageous. A demonstrated approach to coherent spin squeezing is to implement a one-axis twisting Hamiltonian [25]: H1−axis = αJθ2. This non-linear Hamiltonian has already been realized for atoms in optical cavities [11, 14, 25, 26], and in several other physical systems [27,28,29]. We elaborate on the requirements for the validity of the effective dynamics considered
Sign-in/Register to view highlights & summary 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.
