Related Experiment Video
Updated: May 7, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Fractal dynamics in chaotic quantum transport.
V Kotimäki1, E Räsänen, H Hennig
1Nanoscience Center, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 17, 2013
Summary
This study presents the first real-space, real-time quantum transport simulations of chaotic dynamics in a 2D stadium cavity. The findings reveal fractal scaling in magnetoconductance, validated by detrended fluctuation analysis.
Area of Science:
- Quantum physics
- Condensed matter physics
- Computational physics
Background:
- Chaotic quantum transport in 2D systems like semiconductor quantum dots has been experimentally studied.
- Real-space quantum simulations of these phenomena have remained a significant challenge.
Purpose of the Study:
- To perform quantum transport calculations in real space and real time for a 2D stadium cavity exhibiting chaotic dynamics.
- To investigate the magnetoconductance properties and fractal scaling in this system.
Main Methods:
- Utilized real-space, real-time quantum transport simulations.
- Applied a range of magnetic fields to analyze magnetoconductance.
- Employed detrended fluctuation analysis (DFA) for fractality calculations.
- Compared DFA results with a standard fractal dimension extraction method.
Main Results:
- Obtained a comprehensive picture of magnetoconductance.
- Demonstrated fractal scaling in the magnetoconductance data.
- Showcased the effectiveness of DFA in interpreting conductance curves.
- Achieved results consistent with previous experimental data.
Conclusions:
- Successfully simulated chaotic quantum transport in a 2D stadium cavity using a real-space model.
- Confirmed fractal scaling in magnetoconductance, highlighting the utility of DFA.
- The simulation results align qualitatively with existing experimental findings.
More Related Videos
Related Concept Videos
02:32The de Broglie Wavelength
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
01:10Entropy Change in Reversible Processes
In the Carnot engine, which achieves the maximum efficiency between two reservoirs of fixed temperatures, the total change in entropy is zero. The observation can be generalized by considering any reversible cyclic process consisting of many Carnot cycles. Thus, it can be stated that the total entropy change of any ideal reversible cycle is zero.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
02:18Interference and Diffraction
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
01:22Carrier Generation and Recombination
Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes.
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
01:21Carrier Transport
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
02:39Entropy
Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...