Negative and positive cross-correlations of current noises in quantum Hall edge channels at bulk filling factor $\nu =1$

Abstract

Cross-correlation noise in electrical currents generated from a series connection of two quantum point contacts (QPCs), the injector and the detector, is described for investigating energy relaxation in quantum Hall edge channels at bulk filling factor [Formula: see text]. We address the importance of tuning the energy bias across the detector for this purpose. For a long channel with a macroscopic floating ohmic contact that thermalizes the electrons, the cross-correlation turns from negative values to the maximally positive value (identical noise in the two currents) by tuning the effective energy bias to zero. This can be understood by considering competition between the low-frequency charge fluctuation generated at the injector, which contributes positive correlation, and the partition noise at the detector, which gives negative correlation. Strikingly, even for a short channel without intentional thermalization, significantly large positive correlation is observed in contrast to negative values expected for coherent transport between the two QPCs.

Spatial and energy resolution of electronic states by shot noise

“…(1) is the essence of the local noise spectroscopy we develop here. Analogous expressions, already contained in the pioneering theory of the local noise probe [26], were later derived for the auto-correlation noise [36] and cross-correlation noise [37] in nonequilibrium Tomonaga-Luttinger liquids for studies of an AC-biased TJ [20], used for quantum tomography purposes [24] and for semiconducting nanowire-based local noise sensors [38,39]. For nonequilibrium f (ε) with possibly many steplike features, each step is associated with the change of the slope in the S I (V ) dependence.…”

“…The approach is quite universal and equally suitable for the measurements of the nonequilibrium configurations created by charge, spin [56] and valley, etc. currents, hence paving the way for the realization of existing [26,36,37,57] and various novel local noise probes. log filter and a power detector.…”

Shot Noise in Mesoscopic Systems: from Single Particles to Quantum Liquids

“…Electron temperature is evaluated from a fit to the experimental data with Eq. (66) [30][31][32]. The amplifier's noise S I amp is obtained by substituting S I th = 4k B T e G into S I amp = S J ( I = 0)/A 2 − S I th .…”

Quantifying nonequilibrium thermodynamic operations in a multiterminal mesoscopic system

“…We concretely use this to evaluate both the conventional efficiencies and their bounds, as well as the proper free-energy efficiencies, which are determined by the temperatures and potentials of resource region and working substance. Such tunnel contacts can also be used as detectors for the local distribution via noise measurements [95][96][97][98][99].…”