Related Experiment Video
Updated: Jul 19, 2025
12:57
Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection
Published on: October 13, 2017
9.2K
Coulomb staircase in an asymmetrically coupled quantum dot.
G McArdle1, R Davies2, I V Lerner1
1School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, United Kingdom.
Summary
We studied Coulomb blockade in quantum dots, finding current-voltage characteristics depend on Fermi and charging energies. A new regime with a single step in the Coulomb staircase was identified.
Area of Science:
- Condensed Matter Physics
- Quantum Computing
- Nanotechnology
Background:
- Coulomb blockade is a phenomenon in quantum dots that restricts electron transport.
- Understanding electron behavior in quantum dots is crucial for developing quantum devices.
- Asymmetric coupling to leads and non-thermalization effects are key factors in quantum dot transport.
Purpose of the Study:
- To investigate Coulomb blockade in quantum dots with asymmetric lead coupling under arbitrary voltage bias.
- To explore the non-thermalization regime of electron dwell time in quantum dots.
- To determine the influence of Fermi energy to charging energy ratio on current-voltage characteristics.
Main Methods:
- Solving the quantum kinetic equation to model electron transport.
- Analyzing current-voltage characteristics under specific energy ratios.
- Focusing on the non-thermalization regime of electron dwell time.
Main Results:
- Current-voltage characteristics are critically dependent on the ratio of Fermi energy to charging energy.
- In the large Fermi energy regime, a standard Coulomb staircase is observed, similar to thermalized systems.
- A novel regime is identified for large charging energy, featuring a single step in the Coulomb staircase.
Conclusions:
- The ratio of Fermi energy to charging energy significantly dictates Coulomb blockade behavior in quantum dots.
- A new non-thermalized regime with a simplified Coulomb staircase is predicted.
- Experimental verification of the identified single-step regime is anticipated.
Related Concept Videos
01:15Coulomb's Law and The Principle of Superposition
9.0K
Coulomb's Law describes the force experienced by two point charges under each other's presence. But what if there are more than two charges? For example, if there is a third charge, does it experience a force that is a simple combination of the individual forces due to the first two charges? Can it be described mathematically?
The Principle of Superposition answers the question. Yes, Coulomb's Law applies to each pair of charges, and the net force on each charge is the vector sum of...
The Principle of Superposition answers the question. Yes, Coulomb's Law applies to each pair of charges, and the net force on each charge is the vector sum of...
9.0K
01:30Coulomb's Law
9.3K
Experiments with electric charges have shown that if two objects each have an electric charge, they exert an electric force on each other. The magnitude of the force is linearly proportional to the net charge on each object and inversely proportional to the square of the distance between them. The direction of the force vector is along the imaginary line joining the two objects and is dictated by the signs of the charges involved.
Newton's third law applies to the Coulomb force — the...
Newton's third law applies to the Coulomb force — the...
9.3K
01:12Fermi Level Dynamics
284
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
284
02:54Trends in Lattice Energy: Ion Size and Charge
24.0K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
24.0K
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.1K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.1K
03:06The Pauli Exclusion Principle
39.0K
The arrangement of electrons in the orbitals of an atom is called its electron configuration. We describe an electron configuration with a symbol that contains three pieces of information:
39.0K