31 citations · 139 across the 24 of their papers we have counts for
24 papers
Postselected amplification and photon recycling applied to optical sensing of magnetic fields
Yazhi Niu, Jialin Li, Lupei Qin +1
We apply the combined technique of postselected amplification and photon-recycling to an optical setup of magnetic field precision measurement. We propose two recycling schemes and…
Optical phase estimation via homodyne measurement in the presence of saturation effect of photodetectors
Jialin Li, Yazhi Niu, Lupei Qin +1
For optical phase estimation via homodyne measurement, we generalize the theory from detector's linear to nonlinear response regime, which accounts for the presence of saturation e…
Postselected amplification applied to Mach-Zehnder-interferometer for phase shift measurement of optical coherent states
J. L. Li, Y. Z. Niu, L. P. Qin +1
We propose a postselected amplification (PSA) scheme for phase shift measurement of optical coherent states when passing through the Mach-Zehnder-interferometer (MZI). Different fr…
Postselected amplification applied to atomic magnetometers
Yazhi Niu, Jialin Li, Lupei Qin +1
We propose to embed the atomic magnetometer (AM) into an optical Mach-Zehnder interferometer (MZI). We analyze the effect of amplification of the Faraday rotation (FR) angle of the…
Enhanced super-Heisenberg scaling precision by nonlinear coupling and postselection
Lupei Qin, Jialin Li, Yazhi Niu +1
In quantum precision metrology, the famous result of Heisenberg limit scaling as (with the number of probes) can be surpassed by considering nonlinear coupling measuremen…
Quantum-coherence-free precision metrology by means of difference-signal amplification
Jialin Li, Yazhi Niu, Xinyi Wang +2
The novel weak-value-amplification (WVA) scheme of precision metrology is deeply rooted in the quantum nature of destructive interference between the pre- and post-selection states…
Quality analysis for precision metrology based on joint weak measurements without discarding readout data
Lupei Qin, Luting Xu, Xin-Qi Li
We present a theoretical analysis for the metrology quality of joint weak measurements (JWM), in close comparison with the weak-value-amplification (WVA) technique. We point out th…
Master equation approach for transport through Majorana zero modes
Jinshuang Jin, Xin-Qi Li
Based on an exact formulation, we present a master equation approach to transport through Majorana zero modes (MZMs). Within the master equation treatment, the occupation dynamics…
Fisher information analysis on post-selection involved quantum precision measurements using optical coherent states
Yingxin Liu, Lupei Qin, Xin-Qi Li
The weak-value-amplification (WVA) technique has been extensively considered and debated in the field of quantum precision measurement, largely owing to the reduced Fisher informat…
Cross-correlation mediated by Majorana island with finite charging energy
Wei Feng, Lupei Qin, Xin-Qi Li
Based on the many-particle-number-state treatment for transport through a pair of Majorana zero modes (MZMs) which are coupled to the leads via two quantum dots, we identify that t…
Cross correlation mediated by distant Majorana zero modes with no overlap
Lupei Qin, Wei Feng, Xin-Qi Li
Existing studies via shot noise calculation conclude that the cross correlation between the currents in the two leads connected by a pair of Majorana zero modes (MZMs) vanishes whe…
Majorana Conductances in Three-Terminal Transports
Xin-Qi Li, Wei Feng, Lupei Qin +1
We consider a two-lead (three-terminal) setup of nonlocal transport through Majorana zero modes (MZMs) and construct a Majorana master equation (which is also valid for small bias…
Weak-value-amplification analysis beyond the AAV limit of weak measurements
Jianhua Ren, Lupei Qin, Wei Feng +1
The weak-value (WV) measurement proposed by Aharonov, Albert and Vaidman (AAV) has attracted a great deal of interest in connection with quantum metrology. In this work, we extend…
Double-dot interferometer for quantum measurement of Majorana qubits and stabilizers
Kai Zhou, Cheng Zhang, Lupei Qin +1
Motivated by the need of quantum measurement of Majorana qubits and surface-code stabilizers, we analyze the performance of a double-dot interferometer under the influence of envir…
Transport Signatures of a Majorana Qubit and Read-out-induced Dephasing
Lupei Qin, Xin-Qi Li, Alexander Shnirman +1
Motivated by recent proposals of Majorana qubits and the read-out of their quantum state we investigate a qubit setup formed by two parallel topological wires shunted by a supercon…
Estimation of parameters in circuit QED by continuous quantum measurement
Cheng Zhang, Kai Zhou, Wei Feng +1
Designing high-precision and efficient schemes is of crucial importance for quantum parameter estimation in practice. The estimation scheme based on continuous quantum measurement…
Gradual partial-collapse theory for ideal nondemolition measurements of qubits in circuit QED
Wei Feng, Cheng Zhang, Zhong Wang +2
The conventional method of qubit measurements in circuit QED is employing the dispersive regime of qubit-cavity coupling, which results in an approximated scheme of quantum nondemo…
Direct measurement of the quantum state of photons in a cavity
Lupei Qin, Zhong Wang, Cheng Zhang +1
We propose a scheme to measure the quantum state of photons in a cavity. The proposal is based on the concept of quantum weak values and applies equally well to both the solid-stat…
Low-field electron mobility of InSb nanowires: Numerical efforts to larger cross sections
Wei Feng, Chen Peng, Shuang Li +1
Within the framework of Boltzmann equation, we present a theory based study for the low-field mobilities of InSb nanowires (InSb NWs) with relatively large cros…
Qubit state tomography in superconducting circuit via weak measurements
Lupei Qin, Luting Xu, Wei Feng +1
The standard method of "measuring" quantum wavefunction is the technique of {\it indirect} quantum state tomography. Owing to conceptual novelty and possible advantages, an alterna…
Exact quantum Bayesian rule for qubit measurements in circuit QED
Wei Feng, Pengfei Liang, Lupei Qin +1
Developing efficient framework for quantum measurements is of essential importance to quantum science and technology. In this work, for the important superconducting circuit-QED se…
Simple understanding of quantum weak values
Lupei Qin, Wei Feng, Xin-Qi Li
In this work we revisit the important and controversial concept of quantum weak values, aiming to provide a simplified understanding to its associated physics and the origin of ano…
Weak values in continuous weak measurement of qubits
Lupei Qin, Pengfei Liang, Xin-Qi Li
For continuous weak measurement of qubits, we obtain exact expressions for weak values (WVs) from the post-selection restricted average of measurement outputs, by using both the qu…
Quantum Bayesian rule for weak measurements of qubits in superconducting circuit QED
Peiyue Wang, Lupei Qin, Xin-Qi Li
Compared with the quantum trajectory equation, the quantum Bayesian approach has the advantage of being more efficient to infer quantum state under monitoring, based on the integra…