1205.4862 (Shuntaro Takeda et al.)

Generation and Dual-homodyne Characterization of Time-bin Qubits with
Continuous-wave Light    [PDF]

Shuntaro Takeda, Takahiro Mizuta, Maria Fuwa, Jun-ichi Yoshikawa, Hidehiro Yonezawa, Akira Furusawa

We demonstrate a generation scheme of highly pure time-bin qubits using continuous-wave light, unlike the conventional pulsed-laser scheme which comes with unavoidable purity degradation. The advantage of our qubit lies in its coherence with continuous waves, which allows dual-homodyne measurement. This enables the complete characterization of the qubits as two-mode states, as well as a flexible analysis equivalent to the conventional photon-detection scheme. The coherence with continuous waves also opens the way for unconditional qubit operations via continuous-variable quantum operations.

View original: http://arxiv.org/abs/1205.4862