Speaker
Description
The field of hybrid optical-microwave technology is advancing rapidly, driven by goals such as integrating telecom wavelength optical fibre networks with superconducting circuit-based quantum technology. We present a new protocol for generating entanglement between microwave and optical modes, with an inbuilt quantum memory. The protocol is a hybrid extension of Rephased Amplified Spontaneous Emission (RASE) [1-3].
Hybrid RASE first creates entanglement between a photonic mode (e.g. generated by collective spontaneous emission from a cavity-coupled optical transition) and an atomic ensemble. The atomic coherence is then mapped to a long-lived nuclear spin transition before being rephased on another atomic transition to generate a second photonic mode (e.g. in the microwave regime).
We analyse the performance of the protocol after solving the time-dependent Heisenberg-Langevin equations using input-output theory [4]. The protocol is particularly well suited to erbium ensembles in crystals, which exhibit narrow transitions at both microwave and optical frequencies, and long nuclear-spin coherence times [5]. We will describe the theoretical framework to optimise the time-separated, hybrid two-mode squeezed state toward efficient, high bandwidth, and high rate entanglement generation. The impact of atomic dephasing and inhomogeneity will be presented, along with a comparison to hybrid two-mode squeezing generated by direct three wave mixing.
We will also discuss our initial steps toward realising this protocol experimentally, through the development of on-chip superconducting resonators for coupling to ensembles of erbium electron spins.
[1] L. A. Williamson et al., New. J. Phys., 16, 073046 (2014)
[2] K. R. Ferguson et al., Phys. Rev. Lett., 117, 020501 (2016)
[3] J. Stuart et al., arXiv:2409.12503 (2024)
[4] C. W. Gardiner et al., Phys. Rev. A, 31, 3761 (1985)
[5] M. Rančić et al., Nat. Phys., 14, 50-54 (2017)
| I am the presenting author | Yes |
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