Coherent rotational states

Luciano Fonda, N. Mankoč-Borštnik, Mitja Rosina

Norma Mankoč Borštnik

Sergey A. Podoshvedov

Gang Ren, Jian-ming Du, Hai-jun Yu

In this paper, we construct and investigate the nonclassical properties of the squeezing and rotating coherent state (SRCS) via a generalized squeezed operator by introducing a novel parameter r. In a particular case r = 0, SRCS reduces to the normal squeezed coherent state (SCS). The influence of r is studied in terms of squeezing and quantum statistical properties. Our results show that in the SCS not only is squeezing enhanced but also is rotated by the parameter r. Our discussion about the fidelity between SRCS and SCS shows that the fidelity values decrease with increasing parameter r. The experimental scheme for producing SRCS is also given via a self-Kerr medium and non-degenerate parametric amplifier.

Tom R. Hepworth, Daniel K. Ruttley, Fritz von Gierke +3 more

Rotational states of ultracold polar molecules possess long lifetimes, microwave-domain coupling, and tunable dipolar interactions. The availability of numerous rotational states has inspired many applications, including simulating quantum magnetism, encoding high-dimensional qudits and generating large synthetic dimensions. However, engineering the coherent superpositions of multiple rotational states needed for these applications is difficult owing to strong differential light shifts. Here, we overcome this challenge using individual molecules confined in near-magic wavelength optical tweezers. Through precision Ramsey spectroscopy, we find the exact magic wavelengths and sensitivities to detuning errors for multiple rotational state superpositions. We find for traps polarised parallel to the quantisation axis, the magic wavelengths are closely clustered enabling long-lived coherence across multiple rotational states simultaneously. Using a generalised Ramsey sequence, we demonstrate second-scale coherent spin-1 dynamics encoded in three rotational states and perform multiparameter estimation. With modest experimental improvements, we predict second-scale coherence across ten rotational states is achievable.

Chon‐Fai Kam, Wei-Min Zhang, D.H. Feng