Emergence of super-Poissonian light from indistinguishable single-photon emitters

The optical interference constitutes a paramount resource in modern physics. At the scale of individual atoms and photons, it is a diverse concept that causes different coherent phenomena. We present the experimental characterization of both coherent and statistical properties of light emitted from ensembles of trapped ions increasing with a number of contributing phase-incoherent independent atomic particles ranging from a single to up to several hundreds. It conclusively demonstrates how super-Poissonian quantum statistics non-trivially arises purely from the finite number of indistinguishable single-photon emitters in the limit of a single detection mode. The achieved new optical emission regime in which these independent atoms contribute coherently to the super-Poissonian statistics provides a new perspective on the emergence of optical coherence at the atomic scale and constitutes a unique toolbox for its generation and control at the most microscopic level

Ion-pair and solvent relaxation processes in aqueous Na2SO4 solutions

The complex dielectric permittivity of aqueous sodium sulfate solutions (0.025 ≤ c/mol dm-3 ≤ 1.6) has been determined in the frequency range 0.2 ≤ ν/GHz ≤ 20 with a commercial dielectric measurement system based on a vector network analyzer. The spectra were supplemented with interpolated literature data at 12 ≤ ν/GHz ≤ 89. To fit the complex permittivity spectra, a superposition of three Debye relaxation processes was necessary. The slow and intermediate dispersion steps are assigned to the tumbling motion of doubly solvent-separated (2SIP) and solvent-shared (SSIP) NaSO4- ion pairs, respectively. The fast process, of amplitude S3, is due to the collective relaxation of the solvent. Effective solvation numbers were deduced from the effect of Na2SO4 concentration on S3. From the ion-pair dispersion amplitudes, S1 and S2, the concentrations c2SIP and cSSIP, and thus the overall stoichiometric stability constant, βNaSO4-, were determine