Realization of high-speed adaptive quantum state estimation

  title={Realization of high-speed adaptive quantum state estimation},
  author={Saki Nohara and Ryo Okamoto and Koichi Yamagata and Akio Fujiwara and Shigeki Takeuchi},
Adaptive quantum state estimation (AQSE) provides the best possible estimation of unknown parameters of quantum states. In implementations of AQSE, half wave plates (HWPs) driven by mechanical rotators are used to change the measurement basis, but these significantly limit the overall speed of the system. Here we report an AQSE system using a liquid crystal retarder (LCR). With precise calibration, the phase accuracy of an LCR can be below 3.6 × 10−3 radians and as low as 1.2 × 10−3 radians… CONTINUE READING