scholarly journals Waiting Time Distributions of Transport through a Two-Channel Quantum System

2020 ◽  
Vol 10 (5) ◽  
pp. 1772
Author(s):  
Weici Liu ◽  
Faqiang Wang ◽  
Ruisheng Liang
Keyword(s):  
Electron Transport ◽  
Quantum System ◽  
Phase Difference ◽  
Waiting Time ◽  
Coulomb Blockade ◽  
Coulomb Repulsion ◽  
Oscillatory Behavior ◽  
Oscillation Phase ◽  
Strong Coulomb ◽  
Coulomb Blockade Regime

In this work, the waiting time distribution (WTD) statistics of electron transport through a two-channel quantum system in a strong Coulomb blockade regime and non-interacting dots are investigated by employing a particle-number resolved master equation with the Born–Markov approximation. The results show that the phase difference between the two channels, the asymmetry of the dot-state couplings to the left and right electrodes, and Coulomb repulsion have obvious effects on the WTD statistics of the system. In a certain parameter range, the system manifests the coherent oscillatory behavior of WTDs in the strong Coulomb blockade regime, and the phase difference between the two channels is clearly reflected in the oscillation phase of the WTDs. The two-channel quantum dot (QD) system for non-interacting dots manifests nonrenewal characteristics, and the electron waiting time of the system is negatively correlated. The different phase differences between the two channels can clearly enhance the negative correlation. These results deepen our understanding of the WTD statistical properties of electron transport through a mesoscopic QD system and help pave a new path toward constructing nanostructured QD electronic devices.

Aharonov-Bohm oscillations in the Coulomb blockade regime

1992 ◽  
Vol 69 (13) ◽  
pp. 1989-1992 ◽  
Author(s):  
R. P. Taylor ◽  
A. S. Sachrajda ◽  
P. Zawadzki ◽  
P. T. Coleridge ◽  
J. A. Adams
Keyword(s):  
Coulomb Blockade ◽  
Coulomb Blockade Regime ◽  
Aharonov Bohm

ANTI-RESONANCES OF TUNNELING THROUGH A QUANTUM WIRE WITH SIDE-COUPLED QUANTUM DOTS

2001 ◽  
Vol 15 (31) ◽  
pp. 4111-4121 ◽  
Author(s):  
JIN-FU FENG ◽  
SHI-JIE XIONG
Keyword(s):  
Quantum Dots ◽  
Single Particle ◽  
Low Temperatures ◽  
Quantum Wire ◽  
Coulomb Blockade ◽  
Destructive Interference ◽  
Channel Network ◽  
Coupled Quantum Dots ◽  
Coulomb Blockade Regime ◽  
Simple Summation

We study the transport properties of electrons in a quantum wire with side-coupled quantum dots in Coulomb blockade regime by the use of the equivalent single-particle multi-channel network and Landauer formula. At low temperatures the calculated dependence of the conductance on the gate voltage of dots exhibits two dips, indicating the destructive interference of the wave directly transmitted through the wire and the wave reflected from the dots. In a wire with more than one side-coupled dots the suppression of conductance is a simple summation of the effects of scattering of all the dots. The possibility of fabricating tunable switch devices by using such structures is discussed.

Experimental Investigation of Fuel Staging Effect on Modal Dynamics of Thermoacoustic Azimuthal Instabilities in a Multi-Nozzle Can Combustor

2021 ◽  
Author(s):  
J. Kim ◽  
W. Gillman ◽  
T. John ◽  
S. Adhikari ◽  
D. Wu ◽  
...  
Keyword(s):  
Standing Wave ◽  
Phase Difference ◽  
Mass Flow ◽  
Flow Rate ◽  
Oscillatory Behavior ◽  
Operating Conditions ◽  
Low Flow ◽  
Azimuthal Mode ◽  
Fuel Staging ◽  
Modal Dynamics

Abstract This paper analyzes the dynamics of unstable azimuthal thermoacoustic modes in a lean premixed combustor. Azimuthal modes can be decomposed into two counter rotating waves where they can either compete and potentially suppress one of them (spinning) or coexist (standing), depending on the operating conditions. This paper describes experimental results of the dynamical behaviors of these two waves. The experimental data were taken at different mass flow rates as well as different azimuthal fuel staging in a multi-nozzle can combustor. It is shown that at a low flow rate with uniform fuel distribution, the two waves have similar amplitudes, giving rise to a standing wave. However, the two amplitudes are slowly oscillating out of phase to each other, and the phase difference between the two waves also shows oscillatory behavior. For an intermediate flow rate, the dynamics show intermittency between standing and spinning waves, indicating that the system is bistable. In addition, the phase difference dramatically shifts when the mode switches between standing and spinning waves. For a high flow rate, the system stabilizes at a spinning wave most of the time. These experimental observations demonstrate that not only the amplitudes of two waves but also the phase difference plays an important role in the dynamics of azimuthal mode. For non-uniform azimuthal fuel staging, the modal dynamics exhibit only an oscillatory standing wave behavior regardless of the mass flow rate. Compared to the uniform fuel staging, however, the pressure magnitude is considerably reduced, which provides a potential strategy to mitigate and/or suppress the instabilities.

scholarly journals Ferromagnetism in multiband Hubbard models: From weak to strong Coulomb repulsion

1996 ◽  
Vol 54 (6) ◽  
pp. 4056-4067 ◽  
Author(s):  
Karlo Penc ◽  
Hiroyuki Shiba ◽  
Frédéric Mila ◽  
Takuya Tsukagoshi
Keyword(s):  
Coulomb Repulsion ◽  
Hubbard Models ◽  
Strong Coulomb

scholarly journals Intelligent Buses in a Loop Service: Emergence of No-Boarding and Holding Strategies

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Vee-Liem Saw ◽  
Luca Vismara ◽  
Lock Yue Chew
Keyword(s):  
Reinforcement Learning ◽  
Phase Difference ◽  
Waiting Time ◽  
Learning Process ◽  
Average Waiting Time ◽  
Bus Stop ◽  
Emergent Behaviour ◽  
Reasonable Amount ◽  
Bus Stops ◽  
Simulation Time

We study how N intelligent buses serving a loop of M bus stops learn a no-boarding strategy and a holding strategy by reinforcement learning. The no-boarding and holding strategies emerge from the actions of stay or leave when a bus is at a bus stop and everyone who wishes to alight has done so. A reward that encourages the buses to strive towards a staggered phase difference amongst them whilst picking up passengers allows the reinforcement learning process to converge to an optimal Q-table within a reasonable amount of simulation time. It is remarkable that this emergent behaviour of intelligent buses turns out to minimise the average waiting time of commuters, in various setups where buses move with the same speed or different speeds, during busy as well as lull periods. Cooperative actions are also observed, e.g., the buses learn to unbunch.

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