Nonzero temperature effects on antibunched photons emitted by a quantum point contact out of equilibrium

Abstract

Electrical current fluctuations in a single-channel quantum point contact can produce photons (at frequency omega close to the applied voltage V x e/hbar) which inherit the sub-Poissonian statistics of the electrons. We extend the existing zero-temperature theory of the photostatistics to nonzero temperature T. The Fano factor F (the ratio of the variance and the average photocount) is <1 for T<T_c (antibunched photons) and >1 for T>T_c (bunched photons). The crossover temperature T_c ~ Deltaomega x hbar/k_B is set by the band width Deltaomega of the detector, even if hbar x Deltaomega << eV. This implies that narrow-band detection of photon antibunching is hindered by thermal fluctuations even in the low-temperature regime where thermal electron noise is negligible relative to shot noise.

4 pages, 2 pages appendix, 3 figures

References in corpus (4)

• Frequency-selective single photon detection using a double quantum dot
• Experimental Test of the High-Frequency Quantum Shot Noise Theory in a Quantum Point Contact
• Antibunched photons emitted by a quantum point contact out of equilibrium
• Detecting THz current fluctuations in a quantum point contact using a nanowire quantum dot