Browsing by Author "Nori, Franco"

Now showing 1 - 3 of 3

Detecting non-Markovian plasmonic band gaps in quantum dots using electron transport
(2009-06-01)
Chen, Yueh-Nan
;
Chen, Guang-Yin
;
Liao, Ying-Yen
;
Lambert, Neill
;
Nori, Franco
Placing a quantum dot close to a metal nanowire leads to drastic changes in its radiative decay behavior because of evanescent couplings to surface plasmons. We show how two non-Markovian effects, band edge and retardation, could be observed in such a system. Combined with a quantum-dot p-i-n junction, these effects could be readout via current-noise measurements. We also discuss how these effects can occur in similar systems with restricted geometries, such as phononic cavities and photonic crystal waveguides. This work links two previously separate topics: surface plasmons and current-noise measurements.
Quantifying the nonclassicality of pure dephasing
(2019-08-22)
Chen, Hong-Bin
;
Lo, Ping-Yuan
;
Gneiting, Clemens
;
Bae, Joonwoo
;
Chen, Yueh-Nan
One of the central problems in quantum theory is to characterize, detect, and quantify quantumness in terms of classical strategies. Dephasing processes, caused by non-dissipative information exchange between quantum systems and environments, provides a natural platform for this purpose, as they control the quantum-to-classical transition. Recently, it has been shown that dephasing dynamics itself can exhibit (non)classical traits, depending on the nature of the system-environment correlations and the related (im)possibility to simulate these dynamics with Hamiltonian ensembles-the classical strategy. Here we establish the framework of detecting and quantifying the nonclassicality for pure dephasing dynamics. The uniqueness of the canonical representation of Hamiltonian ensembles is shown, and a constructive method to determine the latter is presented. We illustrate our method for qubit, qutrit, and qubit-pair pure dephasing and describe how to implement our approach with quantum process tomography experiments. Our work is readily applicable to present-day quantum experiments.
Simulating Open Quantum Systems with Hamiltonian Ensembles and the Nonclassicality of the Dynamics
(2018-01-19)
Chen, Hong-Bin
;
Gneiting, Clemens
;
Lo, Ping-Yuan
;
Chen, Yueh-Nan
;
Nori, Franco
The incoherent dynamical properties of open quantum systems are generically attributed to an ongoing correlation between the system and its environment. Here, we propose a novel way to assess the nature of these system-environment correlations by examining the system dynamics alone. Our approach is based on the possibility or impossibility to simulate open-system dynamics with Hamiltonian ensembles. As we show, such (im) possibility to simulate is closely linked to the system-environment correlations. We thus define the nonclassicality of open-system dynamics in terms of the nonexistence of a Hamiltonian-ensemble simulation. This classifies any nonunital open-system dynamics as nonclassical. We give examples for open-system dynamics that are unital and classical, as well as unital and nonclassical.