Continuous variable (CV) quantum computation over the optical frequency comb

Anonymous

Xinchao Ruan, Sha Xiong, Hang Zhang +2 more

Moran Chen, Olivier Pfister

Youbin Yu, Xiaomin Cheng, Huaijun Wang +5 more

Continuous-variable (CV) entanglement frequency comb can be produced by enhanced Raman scattering in an above-threshold optical oscillator cavity in which a hexagonally-poled LiTaO3 crystal resides as a Raman gain medium. The Stokes and anti-Stokes Raman signals are enhanced by a coupled quasi-phase-matching optical parametric process and the entanglement natures among these Raman signals and pump are demonstrated by applying a sufficient inseparability criterion for CV entanglement. Such entanglement frequency comb source with different frequencies and continuously tunable frequency interval may be very significant for the applications in quantum communication and networks.

Jing Zhang, Yanfang Wang, Xiaoyu Liu +1 more

Quantum entangled states, especially those having particular properties, are key resources for quantum information and quantum computation. In this paper, we put forward a new scheme to produce 31 continuous–variable (CV) tripartite entanglement fields based on three optical frequency combs via cascade nonlinear processes in an optical parametric cavity, and investigate the spectral characteristics of three frequency combs. The center wavelengths of the three combs are designed as 852 nm, 780 nm (atomic transition lines), and 1550 nm (fiber communication wavelength). The positivity under partial transposition (PPT) criterion, which is sufficient and necessary, is used to evaluate the entanglement in each group of comb lines. This scheme is experimentally feasible and valuable for constructing quantum information networks in future.

Ivan B. Djordjević