Population Oscillations and Ubiquitous Coherences in Multilevel Quantum Systems Driven by Incoherent Radiation.

Area of Science:

• Quantum mechanics
• Molecular physics
• Quantum optics

Background:

• Multilevel quantum systems, such as molecules with multiple vibronic states, are susceptible to incoherent excitation.
• Understanding the role of noise in quantum dynamics is crucial for controlling quantum systems.

Purpose of the Study:

• To investigate the generation of noise-induced coherences in multilevel quantum systems.
• To explore the impact of these coherences on population dynamics and quantum interference.
• To provide insights for the experimental detection of coherent dynamics in complex quantum systems.

Main Methods:

• Analysis of the geometric constraints of the matter-field coupling operator.
• Theoretical modeling of incoherent excitation in multilevel systems.
• Examination of quantum interference effects arising from coherence transfer.

Main Results:

• Noise-induced coherences are guaranteed in systems with four or more incoherent transitions between energy eigenstates due to geometric constraints.
• Noise-induced coherences can drive population oscillations through quantum interference.
• Coherence transfer between ground and excited state manifolds plays a key role in these dynamics.

Conclusions:

• The study reveals a fundamental mechanism for generating quantum coherences from noise in complex quantum systems.
• The findings offer a pathway for experimentally observing and utilizing noise-induced coherent dynamics.
• This work has implications for quantum control, quantum information processing, and understanding decoherence in molecular systems.