Statistics of radiation emitted from a quantum point contact

Abstract

We analyze the statistics of the electromagnetic radiation emitted from electrons pushed through a quantum point contact. We consider a setup implemented in a two-dimenional electron gas (2DEG) where the radiation manifests itself in terms of 2D plasmons emitted from electrons scattered at the point contact. The bosonic statistics of the plasmons competes with the fermionic statistics of the electrons; as a result, the quantum point contact emits non-classical radiation with a statistics which can be tuned from bunching to anti-bunching by changing the driving voltage. Our perturbative calculation of the irreducible two-plasmon probability correlator provides us with information on the statistical nature of the emitted plasmons and on the underlying electronic current flow.

Noise Intensity-Intensity Correlations and the Fourth Cumulant of Photo-assisted Shot Noise

“…This has to be taken into account when comparing the data with theories such as242627 which consider photon detectors. In particular, the correlations between photon detectors will involve other current correlators33.…”

“…Since power fluctuations of Gaussian noise are independent at all frequencies, our measurement probes only the non-Gaussian part of current fluctuations. This technique has been applied many times to the study of 1/ f noise in glassy or disordered materials20212223 and has been proposed to measure the fourth cumulant of a quantum point contact without ac excitation24. In optics, G 2 corresponds to intensity-intensity correlations, a usual probe of the statistical properties of light25.…”

“…In the optics community, current/voltage fluctuations, which are simply another point of view of a fluctuating electromagnetic field, are rather thought of as time dependent electric and magnetic fields. Thus, a noisy electronic device is also a light source, and it is natural to apply tools developed in optics to analyze high frequency electronic noise242627. This point of view will also be studied.…”

Scattering matrix approach to the description of quantum electron transport

“…It has been found that, by developing the theory of emission of photons (or other electromagnetic modes, for example, plasmons) by coherent conductors, it is possible to express photon emission rates [104] or correlators of the number of photons at different points [167,168] in terms of scattering matrices in the conductor. It has been found that, by developing the theory of emission of photons (or other electromagnetic modes, for example, plasmons) by coherent conductors, it is possible to express photon emission rates [104] or correlators of the number of photons at different points [167,168] in terms of scattering matrices in the conductor.…”

Cavity squeezing by a quantum conductor

“…Experiments have been realized with metallic tunnel junctions connected to a resonating line [19], or with quantum dots, realized in carbon nanotubes, nanowires or two-dimensional electron gases [20][21][22][23][24][25][26] embedded in high-finesse coplanar cavities. The interplay of electron transport and emission of photons can lead to an electronic-induced lasing state in the cavity [27][28][29][30], and more generally produce bunched or antibunched photons [31][32][33][34][35], and nonclassicality in the light emitted by a quantum conductor [36,37]. Squeezed light emitted by a tunnel junction was recently demonstrated experimentally in the absence of a cavity [38][39][40].…”