Questions tagged [quantum-dots]
26 questions
6
votes
1 answer
Dispersive regime and resonator frequency pull
I have come across terms such as "dispersive regime" and "dispersive measurement" often.
To understand this, I have been reading this, this, and this.
In the first paper, the gist I got is the following:
In the dispersive regime, the qubit is…
Blackwidow
- 563
4
votes
1 answer
Are electrons in a semiconductor quantum dot is a real electron or just a quasiparticle with a well-defined spin?
It seems there is a consensus that in the gate-defined quantum dot exists isolated electron with well-defined spin. And I understand that by tuning the voltages applied to the 2DEG at quantum well, the isolated island of charge distribution can be…
Neophyte
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4
votes
1 answer
Interference of single photons emitted from solid state sources
Solid state emitters such as quantum dots are thought of as being amongst the best single photon sources for quantum technology.
There have been impressive demonstrations of >10 photon experiments with a quantum dot (most recently arXiv:1910.09930)…
ChrisM
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3
votes
1 answer
Coupling strength $g$ in various contexts
I've come across the term coupling strength $g/2\pi$ in various contexts (transmon, quantum dots, optomechanics etc)
Also, I've come across coupling term $J$ (exchange coupling) a lot.
I think in some sense, these coupling terms mean the same thing…
Blackwidow
- 563
2
votes
2 answers
How to prove that a Hamiltonian is $SU(4)$ invariant?
I am studying the following hamiltonian, consisting of a double quantum dot system
\begin{align}
\hat{H}_{2QD} = \sum_{i=1,2}v_{i}\hat{n}_{i}+\sum_{i=1,2}U_{i}\hat{n}_{i\uparrow}\hat{n}_{i\downarrow} + U_{12}\hat{n}_{i}\hat{n}_{j}
\end{align}
where…
2
votes
0 answers
Has anyone come across the relationship between Higher order confinement wave-functions and corresponding Zeeman Interaction?
I'm studying a hole quantum dot in Germanium. The problem is described in the Luttinger Spin-3/2 basis and takes Fock-Darwin states as solutions in the Quantum Dot plane(xy plane). Furthermore, I assume an external artificial harmonic oscillator…
Retalativity
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2
votes
0 answers
Golden quantum dots blinking and plasmons
I have been reading this article about golden QD as a way to avoid QD blinking. I understand that the surface plasmons here act as a nano antenna which strongly concentrates the light, but I don’t really understand what happens to the emission-…
Shay Kaha
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2
votes
2 answers
Bound states on a Quantum Dot and Tunneling on and off the Dot
Question is essentially: How can the states on a quantum dot be bound when we can tunnel onto them? If plane wave states can tunnel onto them, these plane waves states and the 'bound' states will have the same energy. Thus we could find a state…
safcphysics
- 171
2
votes
2 answers
Chemical potentials of source and drain
I'm trying to learn the concept of quantum dots and coulomb diamonds, and I'm trying to read this but I have encountered a problem which I couldn't find answer online. On the 4th page it mentioned:
By tuning the gates it is possible to tune…
Frank Wang
- 111
2
votes
0 answers
Phonons in quantum dots
If my understanding is correct, quantum dots are tiny crystals where the confined electronic degrees of freedom have discrete energy levels. In this paper Phys. Rev. B 65, 195313 (2002), and many others, electron-phonon coupling is discussed in the…
lakehal
- 636
2
votes
1 answer
What is the difference between Quantum Dots and nanoparticles?
As far as I understand, both quantum dots and nanoparticles are mainly characterised by the fact that all three dimensions are in the nanoscale. Quantum dots are always mentioned to be made from a semiconductor, while nanoparticles can be anything…
DK2AX
- 4,860
1
vote
0 answers
Two-band model for semiconductors and hole picture
I was reading Czycholls Solid State Theory 1 for my Quantum Dot reasearch and came across the two band Hamiltonian with hole operators. After I changed the valence band electron operators to valence band holes I got Delta-Terms after I tried to…
1
vote
0 answers
Beginner Project on Simulating Quantum Dots for Qubits – Recommended Resources and Software
I’m interested in starting a project to simulate quantum dots for qubit applications, namely exploring coupled quantum dots for two-qubit gates. (You can suggest me other similar projects too). While I have some familiarity with quantum computing…
tra sh
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1
vote
0 answers
What is the reason for discreteness in energy level when an electron (electron-hole pair) is confined?
I studied about quantum confinement for a presentation on Quantum Well, wire and dots and came across a term 'Quantum Confinement', it said quantum confinement leads to discrete in energy level. And confinement occurs when the de-Broglie wavelength…
Udit Chauhan
- 21
1
vote
1 answer
Electronic Band Structure in 0D, 1D and 2D materials
Quantum dots have discrete electronic band structures (see https://www.worldscientific.com/doi/pdf/10.1142/9789814397988_0004#:~:text=In%20the%20quantum%20dot%2C%20there,4.1) due to having very few interacting atoms, this leads me to think thin…
Christopher Jacobs
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