Noise-induced Coherent Dynamics of Multilevel Quantum Systems Driven by Incoherent Light: A Case Study of the Three-level V-system

Suyesh Koyu, Timur V. Tscherbul

Xiangming Hu, Ling-bo Kong, Li Wang

Amro Dodin, Timur V. Tscherbul, Paul W. Brumer

We consider incoherent excitation of multilevel quantum systems, e.g., molecules with multiple vibronic states. We show that (1) the geometric constraints of the matter-field coupling operator guarantee that noise-induced coherences will be generated in all systems with four or more incoherent transitions between energy eigenstates and (2) noise-induced coherences can lead to population oscillations due to quantum interference via coherence transfer between pairs of states in the ground and excited manifolds. Our findings facilitate the experimental detection of noise-induced coherent dynamics in complex quantum systems.

Ilya Sh. Averbukh, V.A. Kovarsky, N. F. Perel'Man

Seyyed Hossein Asadpour, Ziauddin Ziauddin, Muqaddar Abbas +1 more

The noise-induced coherence created via the quantum interference of incoherent radiation in atomic three-level systems of V and \ensuremath{\Lambda} types driven by a pair of weak laser pulses is shown to result in exchange of optical vortices. In the three- level V-type atom-light coupling the system is populated in its ground level, while in the \ensuremath{\Lambda} model the system is initially prepared in an electromagnetically induced transparency state. By solving the quantum optical Maxwell-Bloch equations and with quantum interference of incoherent radiation present, we show that the orbital angular momentum (OAM) of the vortex probe beam can be transferred to a generated signal field. While the exchange efficiency in the V configuration is higher, the losses are less in the \ensuremath{\Lambda} scheme when we consider such a noise-induced coherence. We further discuss the effects of phase mismatching and inhomogeneous broadening on the energy conversion between light beams carrying OAM.

Timur V. Tscherbul, Paul W. Brumer

We present a theoretical study of noise-induced quantum coherences in a model three-level $V$-type system interacting with incoherent radiation, an important prototype for a wide range of physical systems ranging from trapped ions to biomolecules and quantum dots. By solving the quantum optical equations of motion, we obtain analytic expressions for the noise-induced coherences and show that they exhibit an oscillating behavior in the limit of large excited level spacing $\mathrm{\ensuremath{\Delta}}$ ($\mathrm{\ensuremath{\Delta}}/\ensuremath{\gamma}\ensuremath{\gg}1$, where $\ensuremath{\gamma}$ is the radiative decay width). Most remarkably, we find that in the opposite limit of small level spacing $\mathrm{\ensuremath{\Delta}}/\ensuremath{\gamma}\ensuremath{\ll}1$, appropriate for large molecules, (a) the coherences can survive for an extremely long time $\ensuremath{\tau}=(2/\ensuremath{\gamma})(\mathrm{\ensuremath{\Delta}}/\ensuremath{\gamma}{)}^{\ensuremath{-}2}$ before eventually decaying to zero, and (b) coherences at short times can be substantial. We further show that the long-lived coherences can survive environmental relaxation and decoherence, suggesting implications to the design of quantum heat engines and to incoherent light excitation of biological systems.