Questions tagged [nanoscience]
The study of the performance of ultra-small structures, materials, and devices, usu. usually 0.1 to 100 nm; also, the study of manipulating materials on an atomic or molecular scale. Nanoscience is sometimes used interchangably with Nanotechnology, which is the manipulation of matter on an atomic and molecular scale.
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Quantum point contacts (QPC) conductance smearing
I have a question regarding the smearing of conductance plateaus of quantum point contacts (QPC).
Conductance plateaus smear if the system is at a finite temperature $T > 0$ K.
What is the exact ...
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Wavefunctions of quantum point contacts
I have a question about the potential and wave functions of discrete energy levels of quantum point contacts. Assuming one has a rectengular potential well:
Can the potential of the QPC be assumed to ...
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What is the difference between nanomaterials and quantum materials? [closed]
As per my knowledge, they are different according to their dimensions only. Can you please explain if I am missing something?
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What photonic properties of a subwavelength plasmonic cavity make it generate saturated structural colour in just one layer?
I have a photonics question regarding a paper I am reading. Physics is not my area of study so please be kind :))
https://doi.org/10.1126/sciadv.adf7207
In this paper, the group has fabricated a self-...
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Why are new compounds in materials science investigated and categorized under low-temperature thermodynamic properties? [closed]
Is it solely because these materials are usually not as interesting in ambient temperatures?
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Why $\rm ZnO$ looks transparent?
I'm looking for the reason transparent of $\rm ZnO$ and found out nanoparticles of $\rm ZnO$ do not scatter reflected light
can I conclude like this: material can be transparent if pass light or ...
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Population inversion requirement for multiexcitonic lasing
I am working with optically active nanomaterials (quantum dots, perovskites), that have pretty large exciton binding energies and can form multiexcitonic complexes, e.g. biexcitons, relatively easily. ...
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How much electricity can be generated from air humidity?
There have been some recent papers on harvesting electrical energy from air humidity using nanoengineered materials:
"Power generation from ambient humidity using protein nanowires" in ...
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Non-equilibrium green method based on the Hamiltonian with non-orthogonal basis
I am thinking about one question. If the Hamiltonian matrix is based on the non-orthogonal basis, how to compute the charge conductance with the non-equilibrium green function (NEGF) method.
Suppose ...
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Charge conductivity by Non-Equilibrium Green Function Method
I am reading the calculation of charge conductivity by Non-Equilibrium Green Function (NEGF) method in this following paper.
Van-Nam Do, Non-equilibirum Green function method: theory and application ...
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What is the mechanism behind the production of carbon nanotubes via laser ablation?
I've been doing some reading on the free-electron laser and its practical applications, one of which seems to be in the (relatively) quick and uniform production of single-wall carbon nanotubes via ...
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Functionalizing iron oxide nanoparticles for antimicrobial activity [closed]
I'm working on my thesis which is about synthesis of iron oxide nanoparticles from a plant leaf extract and testing the particles activity on bacteria to measure their toxicity towards it. The thing ...
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Plasma oscillations in a cylindrical rod [closed]
I have been stuck on this one question for ages, and cannot find the right approach
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Would electrostatic charging break apart the configuration of hexagonal 2D nanosheet materials such as graphene?
Would electrostatically charging a 2D sheet of a material such as graphene, which is sp2 hybridized, wether by induction or conduction, break apart the sigma bonds between the Carbon atoms in the ...
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Is it possible to obtain the next stationary states while plotting electron density in channel of a MOSFET?
Attached is the plot of electron density w.r.t channel
and according to particle in a box/finite well potential method we know this is the first stationary state ($n=1$), I would like to get plot for ...
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What is the difference between demagnetizing tensor vs demagnetizing factor
I know the first one is a tensor that basically shows components and the second is a scalar. Problem is some references call factor to the tensor and others call demagnetizing factor to the components ...
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What is the result of replacing potential function in time independent Schrodinger's wave equation by the potential function in Poisson's equation?
I have to couple above two equations
and put the value of V from Poisson's to Schrodinger's equation and I am doing so to understand the mechanics of MOSFETs.
I have studied most topics in quantum ...
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How do defects in a superconducting nanostructure affect the supercurrent?
I was wondering how point defects in a superconducting nanowire affect the supercurrent flowing through this wire.
In a naive view I am expecting the defect to decrease the maximum current allowed in ...
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What is difference between Quantum optics and photonics in general?
Might be a vague Question, But I'm hard to understand it.
My Interest is Quantum optics, which studies Atom optics, Optical coherence, and experimentally proven foundations of Quantum Mechanics.
...
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Informations about non-Markovianity? [closed]
What are the examples of the practical implementations of studying the non-Markovian dynamics of such open quantum system (e.g. quantum dot)?
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Quantum dots applications [closed]
I wanna find some interesting project for my master thesis concerning quantum dots, meanwhile I'm learning open quantum dynamics (Markovian & non-Markovain). Is there some ideas to combine these ...
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Why is nano-meter technology not used to jam more coils into incandescent light-bulbs as done with semiconductors?
Why is nano-meter technology not used to fit coils into incandescent light-bulbs?
I know we use nano-meter technology to fit more transistors into a small area on a silicon chip, but why do we not use ...
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Can we synthesis pico materials or femto materials?
Currently we know that the radius of an atom is of the order $10^{-10} m$ and nucleus' radius is of the order $10^{-15}m.$ We also know that nano-materials does exist and can be synthesised by various ...
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For a quantum system with two contacts, how does one construct the contact hamiltonian for NEGF transport?
For context, I have been going through Supriyo Datta's NEGF course, slides, lecture material, and have been learning how to simulate quantum transport in his formalism.
For simplicity, consider a 1D-...
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Would a wireless (stringless) Yo-yo be possible? [closed]
I have this interesting idea for a toy (not a real one, it's for a story). It's a stringless yo-yo that uses electromagnetism to mimic a regular yo-yo.
The user wears a ring on their middle finger ...
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Can second harmonic generation be stronger than fundamental frequency interaction in metals/dielectric nanoparticles?
Quick question regarding non-linear optics:
A nanoparticle, either dielectric or metallic present second harmonic generation. The dielectric, following the simplest modelization as:
$$E(2\omega)\...
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Carbon nanotube hydrophobicity
Xinyou Ma, Chenghan Li, Alex B. F. Martinson and Gregory A. Voth, Water Assisted Proton Transport in Confined Nanochannels
states that carbon nanotube is hydrophobic. That means, as I understand it, ...
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Can nanotechnology build a virus? [closed]
I heard that nanotechnology can arrange atoms the way one wishes. The atomic force microscope can control the arrangement. As the composition of the viruses is known, can by nanoprinting a virus be ...
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Can sound be used to identify a molecule?
A few notes to this:
Can a molecule have a particular "response" to sound? I understand
that soundwaves arise from the synchronisation of millions of
particles but assuming such a fine ...
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What are the steps that give rise to this following resistance equation for a diffusive transport of electrons?
$ R = R_b (1 + \frac{\lambda}{L})$
Source - page 6 of this book: https://nanohub.org/courses/FON1/01a/asset/15698
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Why is the Fermi wavelength in a semiconductor larger than in a metal?
I am a high school student, trying to better understand quantum point contacts. Would appreciate a simple explanation if possible.
Source: https://arxiv.org/abs/cond-mat/0512609
Since the conductance ...
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Are quantum dot’s immobile?
In a recently closed question regarding the cooling of quantum dots through lasers has one of the commentators state that this is in fact impossible as QD’s are immobile:
Can quantum dots temperature ...
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What is wrong in this example with Heisenberg principle?
On Heisenberg principle
Suppose an electron is beamed in a nanotube with (width $\Delta x$) on which has been applied a negative voltage so the walls are repealing the electron and it can not approach ...
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Can electromagnetic standing waves be used to move particulates?
As detailed in this paper:
https://www.researchgate.net/publication/3941396_Ultrasonic_separation_of_suspended_particles
The researchers use the formation of acoustic standing waves to deposit ...
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What dimensions would a quantum confinement system have to be for its electromagnetic emission spectrum to be in the radio section?
Just as specific dimensional restrictions on systems that have quantum confinement like quantum dots lead to the tenability of the emission spectrum of such a system, I was wondering how this idea ...
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Would a macroscopic sphere with the thicknesss of a few atoms behave as an artificial atom?
As quantum dots are composed of closely packed atoms, where their electronic levels are bound and in a confined system, would a similar system, with the same thickness as a quantum dot but much larger ...
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Practical to measure topography of a large area (mm-scale) with scanning probe microscopy (SPM)?
I'm currently very new to nanotechnology. I do understand that it is possible to achieve an excellent topography image of a sample by SPM. However, is it possible to do SPM over a large area (for ...
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Silicon Nano materials
Bulk Si has indirect bandgap structure. But when we make Si into nano particles it behaves like a direct bandgap. Why?
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One Dimensional Heterostructures
Van Der Walls Heterostructures stack different single layer materials together.
However, just as a layer of various graphene sheets form graphite with weak bonding in between making the layers easily ...
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Variables in Photoionization and Work Function of metals
Do metals engaged in coordination bond have the same work function and/or photoionization of the pure metal? The outer electron shell still remains the same.
If photoionization were to happen, what ...
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Low cost Ultra High Vaccum Chamber and Atomic Force Microscope
Is it possible to build low cost Ultra High Vacuum Chambers and Atomic Force Microscopes?
I found a publication about a low cost AFM and I also found instructions for a Ultra High Vacuum chamber. ...
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How do I determine which surface energy of a crystal silicon planes is the lowest? [closed]
If a thin 8” Diameter Single Crystal Silicon (001) substrate is accidentally dropped onto a concrete floor, it will break apart into pieces.
By considering only the surface energies of (001), (110) ...
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Could a nanoscopic grain of tungsten moving at ludicrous speed make a sonic boom?
Writing a scifi story about a civilization with mature nanotechnology. Grain of tungsten is a proxy for a nanite.
If such a tiny thing as a nanogram of tungsten somehow got accelerated to some truly ...
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How to ease/reduce surface roughness caused by ion sputtering?
I want to investigate the electron emission of samples under electron bombardment.
Experts will know that surface condition plays a huge role in the emission rate and some other properties (e.g. max ...
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What causes materials like Vantablack to have their high optical absorption properties?
As per the title of this post. From reading, I understand that blackbody radiation is a factor I should consider here, with light being absorbed and converted to heat etc.
However, what I want to ...
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Metasurface holography as a principle behind volumetric displays?
Disclaimer: By no means am I a physicist of any kind so complete inability to grasp complex physical concepts without spending ridiculously unreasonable amounts of time on corresponding research is a ...
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How is ECR (Electron Counting Rule) done in a structure?
I've been told how to apply the ECR to GaAs{001}(2×4) in my lectures but it makes no sense to me and I don't seem to be able to find any other sources that explain this. (This is a further question on ...
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Can we connect several Nano Spacecraft moving at 20% speed of light? [closed]
Nano spacecrafts are one gram silicon chips that will be accelerated to 20% of the speed of light to reach Alpha Centauri in 20 years.
I wonder could we connect several spacecraft after they were ...
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Which is the correct GaAs{001}(2×4) structure?
When trying to understand the GaAs 2x4 surface reconstruction, I came across the following statement:
"Because the periodicity of the surface has doubled (compared to the bulk periodicity) in the ...
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Does the Thomas-Fermi screening length formula only apply to metals?
Does the Thomas-Fermi screening length formula only apply to metals?
In my notes, the Thomas-Fermi screening length is:
$\lambda_{TF}^2 = \left(\frac{\pi}{6}\right)^{1/3} \frac{\epsilon(0) a_0}{4n^{1/...
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