We investigate the shot noise generated by particle emission from a mesoscopic capacitor into an edge state reflected and transmitted at a quantum point contact (QPC). For a capacitor subject to a periodic voltage the resulting shot noise is proportional to the number of particles (both electrons and holes) emitted during a period. It is proportional to the product of transmission and reflection probability of the QPC independent of the applied voltage but proportional to the driving frequency. If two driven capacitors are coupled to a QPC at different sides then the resulting shot noise is maximally the sum of noises produced by each of the capacitors. However the noise is suppressed depending on the coincidence of the emission of two particles of the same kind. Of high interest are dynamic current quantization phenomena. This quantization is governed by the number of particles participating in the transport during some fixed time interval (e.g., the driving period of a pump [8]). A quantized dc current was experimentally observed in a Coulomb blockade turnstile [9], in a one-dimensional channel under the action of surface acoustic waves [10], and recently in a 1D channel subject to either two local potentials oscillating out of phase [11] or a single oscillating potential [12]. Importantly a quantized ac current generated by a quantum capacitor subject to large amplitude excitation was observed [13] and discussed [14,15].These phenomena deal with the measurement of single particle observables, like the current. We show in this Letter that the noise, essentially a two-particle phenomenon, can exhibit a quantization behavior as well.We consider the system, Fig. 1, consisting of two quantum capacitors connected to different linear edge states which in turn are coupled via a central quantum point contact (QPC). In the regime when either one of the quantum capacitors (or both) generate a quantized ac current [13] induced by an oscillating back-gate potential the shot noise, as we show, is quantized. If the transmission T α of a QPC connecting the capacitor α = L, R to the linear edge state is small, T α → 0, and the amplitude of the driving potential V α (t) = V α,0 + V α,1 cos(Ωt + ϕ α ) is large compared to the level spacing ∆ α then for small frequency n α = [2V α,1 /∆ α ] electrons (here [X] is the inte- ger part of X) and n α holes are emitted during a driving period T = 2π/Ω. We show that, if the emission of particles is not simultaneous, the zero-frequency correlator P 12 of currents flowing into the leads 1 and 2 iswhere N = 2n L + 2n R is the total number of particles (electrons and holes) emitted during a driving period, P 0 = (2e 2 /h)T C R Ch Ω, with T C , R C being transmission and reflection probabilities of the central QPC connecting the two linear edge states, see Fig. 1. Note that the noise produced by the source α alone is: P α,12 = −2n α P 0 . If two electrons (or two holes) emitted by different sources arrive at the central QPC at the same time then the noise will be suppressed. The difference δ...

We consider two driven cavities (capacitors) connected in series via an edge state. The cavities are driven such that they emit an electron and a hole in each cycle. Depending on the phase lag the second cavity can effectively absorb the carriers emitted by the first cavity and nullify the total current or the set-up can be made to work as a two-particle emitter. We examine the precision with which the current can be nullified and with which the second cavity effectively counts the particles emitted by the first one. To achieve single-particle detection we examine pulsed cavities.

The room-temperature dependences of the Seebeck coefficient, Hall coefficient, electrical conductivity, charge carrier mobility, and thermoelectric power factor were obtained as a function of thickness d (d = 8 nm to 400 nm) of PbTe epitaxial layers grown by thermal evaporation in vacuum of PbTe polycrystals doped with Na onto (100)KCl surfaces and covered with an Al 2 O 3 layer. Distinct oscillations in the d-dependences of the properties were observed and attributed to the size quantization of the energy spectra in PbTe layers. The experimental values of the oscillation period are in good agreement with the results of theoretical calculations using the effective-mass approximation and a model for a rectangular potential well with infinitely high walls. It follows from the obtained results that quantization of the energy spectrum in PbTe thin-film structures occurs not only for the electron gas but also for the hole gas.

It is established that the room-temperature dependences of transport properties on the total thickness of PbSe layers d in PbSe/EuS superlattices exhibit an oscillatory behavior. It is shown that the oscillation period Δd practically coincides with the period of the thickness oscillations observed earlier in single PbSe/EuS quantum well. The non-monotonic character of these dependences is attributed to quantum size effects. The theoretically estimated and experimentally determined Δd values are in good agreement.