Squeezed comb states. (arXiv:2009.12888v1 [quant-ph]) Leave a comment

Continuous-variable codes are an expedient solution for quantum information
processing and quantum communication involving optical networks. Here we
characterize the squeezed comb, a finite superposition of equidistant squeezed
coherent states on a line, and its properties as a continuous-variable encoding
choice for a logical qubit. The squeezed comb is a realistic approximation to
the ideal code proposed by Gottesman, Kitaev and Preskill, which is fully
protected against errors caused by the paradigmatic types of quantum noise in
continuous-variable systems: damping and diffusion. This is no longer the case
for the code space of finite squeezed combs, and noise robustness depends
crucially on the encoding parameters. We analyze finite squeezed comb states in
phase space, highlighting their complicated interference features and
characterizing their dynamics when exposed to amplitude damping and Gaussian
diffusion noise processes. We find that squeezed comb state are more suitable
and less error-prone when exposed to damping, which speaks against standard
error correction strategies that employ linear amplification to convert damping
into easier-to-describe isotropic diffusion noise.

Leave a Reply

Your email address will not be published. Required fields are marked *