Boson sampling with Gaussian measurements

Autor: Chakhmakhchyan, Levon, Cerf, Nicolas J.
Rok vydání: 2017
Předmět:
Zdroj: Phys. Rev. A 96, 032326 (2017)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevA.96.032326
Popis: We develop an alternative boson sampling model operating on single-photon states followed by linear interferometry and Gaussian measurements. The hardness proof for simulating such continuous-variable measurements is established in two main steps, making use of the symmetry of quantum evolution under time reversal. Namely, we first construct a twofold version of scattershot boson sampling in which, as opposed to the original proposal, both legs of a collection of two-mode squeezed vacuum states undergo parallel linear-optical transformations. This twofold scattershot model yields, as a corollary, an instance of boson sampling from Gaussian states where photon counting is hard to simulate. Then, a time-reversed setup is used to exhibit a boson sampling model in which the simulation of Gaussian measurements -- namely the outcome of eight-port homodyne detection -- is proven to be computationally hard. These results illustrate how the symmetry of quantum evolution under time reversal may serve as a tool for analyzing the computational complexity of novel physically-motivated computational problems.
Comment: 8 pages, 3 figures. Updated version for publication
Databáze: arXiv