Heisenberg-Type Quantum Steering by Continuous Weak Measurement in Circuit QED *

Zhong Wang

Fig. 2 (Color online) Evolution of several typical steering parameters $S_{ijk}^{mnl}$. Subscripts for observables $x$, $y$ and $z$, superscripts for measurement methods $\varphi_1$ and $\varphi_2$. (a) $S^{112}_{xyz}$ cannot violate the steering inequality. (b) $S^{121}_{xyz}$ violates the steering inequalities after a period of evolution. The minimum is $-0.31$. (c) $S^{121}_{zxy}$ violates the inequality only when oscillating to valleys before getting into steady state. The minimum is $-0.11$. Evolution times in (a), (b) and (c) are from 0 to 5 $\mu$s. (d) $S^{121}_{zxy}$ from 0.3 $\mu$s to 0.7 $\mu$s, i.e., the vertical black lines in (c), in which the steering inequality is violated intermittently. System parameters are the same as Fig. 1.