Comparing the quantum witness, the entropic Leggett-Garg inequality and the NCGD.

In this paper, we investigate the violation of the quantum witness, the entropic Leggett-Garg inequality (LGI) and the no-coherence-generating-and-detecting (NCGD) dynamics, under projective and coarsening measurements. We consider a qubit in the three scenarios: coherent dynamics, in the presence of dissipation, and in the presence of dephasing. For the pure qubit, we find that in the case of the projective measurement, the non-violation conditions of the quantum witness and the NCGD are the same; while the non-violation conditions of the entropic LGI and the quantum witness do not contain each other, i.

Efficient and systematic parameter extraction based on rate equations by DFB equivalent circuit model.

The conventional direct parameter extraction method generally suffers from cumbersome due to redundant experiments. An efficient and systematical parameter extracting solution is proposed based on an equivalent circuit model of distributed feedback (DFB) lasers. The successfully built circuit model includes the necessary intrinsic parameters in the rate equations and the extrinsic parameters to provide a better approximation of the actual laser.

Quantum violation of LGI under an energy constraint for different scenarios systems.

In this paper, we consider a qubit in four scenarios: with drive, without drive, and in the presence of dissipation and dephasing, to investigate the quantum violation of the Leggett-Garg inequality (LGI) in an energy constraint. In the case of the energy constraint, we find that under the coarsening measurement in reference and final resolution, the quantum violation of the LGI for the pure qubit is the most robust; on the other hand, the quantum violation of the LGI for the dephasing qubit is the most vulnerable, and the quantum violation of the LGI for driven qubit lies between that of pure qubit and dissipation qubit. Under the coarsening of measurement temporal reference, the quantum violation of the LGI for the pure qubit is more robust than that of the qubit with driven.