Breaking Lorentz reciprocity to overcome the time-bandwidth limit in physics and engineering

Area of Science:

• Physics and Engineering
• Photonics and Optics
• Quantum Mechanics
• Acoustics and Mechanics

Background:

• A long-standing principle states that system bandwidth (Δω) and interaction time (Δt) are inversely proportional (Δt·Δω ~ 2π).
• This fundamental limit, derived from Fourier reciprocity, restricts capabilities in diverse fields like photonics, optomechanics, and atomic physics.
• Existing resonant and wave-guiding systems are constrained by this time-bandwidth product limitation.

Purpose of the Study:

• To challenge the fundamental time-bandwidth product limit in wave-system interactions.
• To explore overcoming this limit in systems where Lorentz reciprocity is broken.
• To theoretically demonstrate enhanced time-bandwidth performance in asymmetric systems.

Main Methods:

• Theoretical analysis of wave-system interactions.
• Investigating the impact of broken Lorentz reciprocity on the time-bandwidth product.
• Modeling a magnetized semiconductor heterostructure with asymmetric transport properties.

Main Results:

• Demonstrated that the conventional time-bandwidth limit can be surpassed.
• Showed that increased asymmetry in transport properties allows greater surpassing of the limit.
• Achieved orders-of-magnitude improvement in the time-bandwidth product using realistic material parameters in the designed heterostructure.

Conclusions:

• The findings revise established paradigms for linear, time-invariant resonant systems.
• Challenges the notion that high-quality resonances must be narrowband.
• Opens possibilities for developing devices with significantly enhanced time-bandwidth performance.