Positive Current Correlations Associated with Super-Poissonian Shot Noise

Noise Correlations in a Coulomb-Blockaded Quantum Dot

“…Results are in good agreement with a multi-level sequential-tunneling model in which electron bunching arises from dynamical chan- nel blockade [11,12]. For weak-tunneling output leads, noise cross-correlation in the three-lead configuration is found to be proportional to the deviation of the autocorrelation from the Poissonian value (either positive or negative) similar to the relation found in electronic Hanbury Brown-Twiss (HBT)-type experiments [3,4,18]. The quantum dot is defined by gates on the surface of a GaAs/Al 0.3 Ga 0.7 As heterostructure [ Fig.…”

“…For similar reasons, Fermi statistics without interactions also induces a negative noise crosscorrelation in multiterminal devices [1,2,3,4]. It is therefore surprising that under certain conditions, the interplay between Fermi statistics and Coulomb interaction can lead to electron bunching, i.e., super-Poissonian auto-correlation and positive cross-correlation of electronic noise.The specific conditions under which such positive noise correlations can arise has been the subject of numerous theoretical [5,6,7,8,9,10,11,12,13,14] and experimental [14,15,16,17,18,19,20,21,22,23] [10,15,24] occurring naturally in these devices. In more controlled geometries, super-Poissonian noise has been associated with inelastic cotunneling [9] in a nanotube quantum dot [20], and with dynamical channel blockade [11,12] in GaAs/AlGaAs quantum dots in the weak-tunneling [21] and quantum Hall regimes [22].…”

“…In more controlled geometries, super-Poissonian noise has been associated with inelastic cotunneling [9] in a nanotube quantum dot [20], and with dynamical channel blockade [11,12] in GaAs/AlGaAs quantum dots in the weak-tunneling [21] and quantum Hall regimes [22]. Positive noise cross-correlation has been observed in a capacitively-coupled double dot [23] as well as in electronic beam-splitters following either an inelastic voltage probe [5,6,7,8,19] or a super-Poissonian noise source [18]. The predicted positive noise cross-correlation in a three-lead quantum dot [12] has not been reported experimentally to our knowledge.…”

“…The specific conditions under which such positive noise correlations can arise has been the subject of numerous theoretical [5,6,7,8,9,10,11,12,13,14] and experimental [14,15,16,17,18,19,20,21,22,23] studies in the past few years. Super-Poissonian noise observed in MESFETs [15], tunnel barriers [16] and self-assembled stacked quantum dots [17] has been attributed to interacting localized states [10,15,24] occurring naturally in these devices.…”

Proposal for detection of non-Markovian decay via current noise

“…For examples, positive correlations due to resonant tunneling states [16], noise enhancement due to quantum entanglement [17], spin-flip co-tunneling processes [18], non-Markovian coupling between dot and leads [19], and quantum shuttle effect [20]. The underlying physical picture in our case maybe similar to a recent work by Djuric et al [21] They considered the tunneling problem through a QD connected coherently to a nearby single-level dot, which is not connected to the left and right leads.…”