6 papers
Quantum nonreciprocity from qubits coupled by Dzyaloshinskii-Moriya interaction
Zhenghao Zhang, Qingtian Miao, G. S. Agarwal
We present a theoretical study of quantum nonreciprocity induced via a Dzyaloshinskii-Moriya interaction (DMI) in an otherwise achiral, waveguide quantum electrodynamics. Using the…
Saturation of Quantum Cramer-Rao Bounds for Distributed Sensing via Error Sensitivity in SU(1,1)-SU(m) Interferometry
Girish S. Agarwal
Breaking the standard quantum limit in the sensing of parameters at different spatial locations, such as in a quantum network, is of great importance. Using the framework of quantu…
Time crystals and nonequilibrium dissipative phase transitions mediated by squeezed bath
Zhenghao Zhang, Qingtian Miao, G. S. Agarwal
Nonequilibrium dissipative phase transition, arising from the competition of cooperative behavior and coherent field driving, discovered in the 1970s by Narducci et al. and Walls e…
Saturation of the Cramér-Rao Bound for the Atomic Resonance Frequency with Phased Array of Hyperbolic Secant Pulses
Tharon Holdsworth, Jacob Adamczyk, Girish S. Agarwal
Precise estimation of the atomic resonance frequency is fundamental for the characterization and control of quantum systems. The resonance experiment is a standard method for this…
Quantum noise induced nonreciprocity for single photon transport in parity-time symmetric systems
Dibyendu Roy, G. S. Agarwal
We show nonreciprocal light propagation for single-photon inputs due to quantum noise in coupled optical systems with gain and loss. We consider two parity-time () sy…
Transparency, Nonclassicality and Nonreciprocity in Chiral Waveguide Quantum Electrodynamics
Qingtian Miao, G. S. Agarwal
We examine quantum statistical properties of transmission and reflection from a chiral waveguide coupled to qubits for arbitrary input powers. We report on several remarkable featu…