Abstract
We present a theoretical study of noise-induced quantum coherences in a model three-level -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 (, where is the radiative decay width). Most remarkably, we find that in the opposite limit of small level spacing , appropriate for large molecules, (a) the coherences can survive for an extremely long time 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.
- Received 1 April 2014
DOI:https://doi.org/10.1103/PhysRevLett.113.113601
© 2014 American Physical Society