Super- and subradiance by entangled free particles

TL;DR

This paper demonstrates that entangled free electrons can exhibit super- or subradiance in light emission, revealing quantum correlations' role beyond classical effects and enabling quantum state-sensitive light control.

Contribution

It introduces the concept that quantum entanglement between free particles influences super- and subradiance, extending understanding beyond classical correlations.

Findings

Entangled electron pairs can produce super- or subradiant emission patterns.

Light spectrum and emission can be reshaped using different electron Bell-states.

Results are applicable to any optical medium and generalize to many-body quantum states.

Abstract

When multiple quantum emitters radiate, their emission rate may be enhanced or suppressed due to collective interference in a process known as super- or subradiance. Such processes are well-known to occur also in light emission by free charged particles. To date, all experimental and theoretical studies of super- and subradiance in these systems involved the classical correlations between the emitters. However, dependence on quantum correlations, such as entanglement between different emitting particles, has not been studied. Recent advances in coherent-shaping of free-electron wavefunctions motivate the investigation of such quantum regimes of super- and subradiance. In this Letter, we show how a pair of coincident path-entangled electrons can demonstrate either super- or subradiant light emission, depending on the two-particle wavefunction. By choosing different free-electron Bell-states, the spectrum and emission pattern of the light can be reshaped, in a manner that cannot be accounted for by a classical mixed state. We show these results for light emission in any optical medium, and discuss their generalization to many-body quantum states. Our findings suggest that light emission can be sensitive to the explicit quantum state of the emitting matter wave, and possibly serve as a non-destructive measurement scheme for measuring the quantum state of many-body systems.