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 ...

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0answers
343 views

Measurement of Tangential Momentum Accomodation?

(this question is a crosspost from theoretical physics.) I am using atomic force microscopy (AFM) for characterizing pores of the size of nanometers for application in gas flow. For this, knowing ...
7
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5answers
1k views

Perpetual motion machine of the second kind possible in nano technology?

First of all sorry for my English - it is not my native language. During my engineering studies at the university the thermodynamics professor told us that the "second law of thermodynamics is not ...
7
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2answers
106 views

Is light red shifted in optical tweezers?

This is a question I put to my supervisor during my PhD many years ago, and never really got a satisfactory answer to. In an optical tweezers, assume that a beam of light is used to move a glass ...
6
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5answers
773 views

Nano-particle or Molecule?

What's the difference between something being labeled a "nano-particle" or it being called a "molecule"?
4
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2answers
780 views

If you had two “perfectly” flat surfaces of the same material?

Let's say you had 2 nano-engineered surfaces of diamond which were as 'flat' as possible (of course considering the radii of each carbon atom in the lattice)... would there be any friction between ...
4
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2answers
365 views

How to determine the (n,m) dimensions of a carbon nanotube?

I've been reading about nanotubes lately, and I keep seeing the $ (n,m) $ notation. How does this describe a nanotube's structure? How do I determine which is $n$ and which is $m$ ? I'm familiar with ...
4
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3answers
591 views

Nanorobots. What stops us from producing them yet?

If we can already predicts accuratelly motion on molecular levels, what stops us from developing small robots to, for instance, navigate through our blood vessels looking for cancerous cells and ...
4
votes
1answer
224 views

Clarification of Landauer approach

I am trying to understand the Landauer approach. Consider the setup: (left contact)-(conductor)-(right contact). For simplicity, the conductor is a 1d wire (the transverse part is not relevant for ...
4
votes
1answer
310 views

Fourier transformation, electric field and magnetic field to have a shielding lattice against particles

With Fourier-Series Expansion, we can write a function as sum of many non-repating different frequncied different amplituded sine and cosine functions. Lets assume we know electric-field and ...
3
votes
1answer
508 views

Nanotube chiral angle as a function of $n$ and $m$

I'm looking into nanotubes and I thought I'd assure myself that the basic geometry equations are indeed correct. No problems for the radius, I quickly found the known formula: $$R = ...
3
votes
2answers
358 views

Nanotechnologies: current problems and general limitations

I have some questions about Nanotechnologies. I'm not physicist and my knowledges about the topic are limited by the "Engines of Creation" book by Eric Drexler. So I think that my questions are ...
3
votes
3answers
122 views

Why can we quantize macro(meso)scopic harmonic oscillator?

It is well known that we have got many kinds of quantized macro(meso)scopic harmonic oscillators or so in tiny mechanical systems. People are talking about cavity cooling and so on. However, it is ...
3
votes
1answer
87 views

Specific Heat of Nano Particles

Specific heat of nano particles is less than bulk specific heat of them. Why?
3
votes
2answers
166 views

Layman's method to sharpen a wire (STM-tip)

We use a platinum-irididum wire to fabricate our STM tips. And by "fabricate" I mean to cut it with really sharp pliers or scissors. Sometimes we get good tips but most of the time they are not usable ...
3
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1answer
207 views

How are quantum potential wells fabricated?

Potential wells, such as infinite and finite potential well, have been the standard examples in quantum mechanics textbooks for tens of years. They started being only theoretical toy models but as ...
3
votes
1answer
287 views

How do High Electron Mobility Transistors (HEMT) work?

I am studying High Electron Mobility Transistors (HEMT), but I simply cannot understand how they work in the way described by the references I've read on the Internet. This is what I understand so ...
3
votes
1answer
101 views

Absorption/Extinction formula of nanoparticles

I know the absorption/extinction equations in nanoparticle physics should be: $$Q_{abs}=\frac{1}{2}\mathbf{Re}\int \mathbf{J}_{tot}\cdot\mathbf{E}_{tot}^\ast ...
2
votes
2answers
3k views

What is the approximate electrical conductivity $\sigma$ of graphene in S/m or S/cm?

I am trying to find an approximate value of the electrical conductivity $\sigma$ of graphene in units of S/m or S/cm. This table on Wikipedia gives $\sigma$ values for a variety of materials ...
2
votes
1answer
34 views

Having nano-scale holes in metal, possible today?

I am considering to design a gas filtering system that is based on the size of gas molecules. Basic idea is to flow mixed gas in a long pipe, and to allow CO2 to get of pipe through nano-size holes ...
2
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2answers
43 views

What is light localisation?

Reading about plasmonic nanoparticles I faced the term "localised light". How can one localise light? What are applications of it?
2
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1answer
41 views

Electric field inside a metal nanoparticle?

In localized surface plasmon resonance, the conduction electrons of a metal nanoparticle oscillate in tune with the frequency of the incident electromagnetic wave . The effect is dominated by ...
2
votes
1answer
852 views

Nanotech - zero dimensional fullerene

Not really a physics junkie, and I think this is a chemistry question, but since there's no chemistry.stackexchange.com (yet) I think here is the best place. I was just reading up on nanotech and ...
2
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0answers
65 views

High Young's Modulus and Tensile Strength of Carbon Nanotubes

I was recently reading about Carbon Nanotubes having extremely high Young's moduli, as well as high Tensile Strength, making them very interesting fibers. However, when I read this I wondered what was ...
2
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0answers
195 views

How to calculate radiative transition rate of exciton in a quantum dot with specific dimension?

I am writing rate equations for a nanophotonic system including three quantum dots. I need to calculate that radiative transition rates of exciton in ground state in those quantum dots. In the paper ...
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vote
1answer
501 views

Why is honeycomb lattice the ideal shape for solar cells?

Quoting this web site (which I haven't thoroughly verified for credibility yet): The material is graphene, also known as graphite, a naturally-occurring mineral that forms a one-atom-thick ...
1
vote
1answer
2k views

What is the electrical conductivity (S/m) of a carbon nanotube?

I have been searching around for a while for this but I am having trouble finding any actual figures, all I can seem to find is that it is "very high". So I am wondering, does anyone have any figures ...
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vote
4answers
216 views

Quantum dots on the nuclear scale!

Quantum dots are quantum systems that are confined by definition on the nano scale. Why didn't people study similar systems on a much smaller scale, something as small as the dimension of the nucleus? ...
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1answer
44 views

Why are carbon nanotubes are so difficult to create?

I have heard that the future of the techonolgy are the carbon nanotubes due to their resistance and conductivity, but why are they so difficult to create?
1
vote
2answers
166 views

Quantization of momentum in nanotubes

I'm reading about carbon nanotubes and how the momentum (lets call it $k_x$) is quantized along the circumferential direction and not along the cylindrical (call this $k_y$). I can follow the maths ...
1
vote
2answers
120 views

Light bending surfaces and energy funneling properties

In the last year there has been fuzz regarding metamaterials studied for the purpose of cloaking, and it seem to me they are somewhat glorified 2D waveguides, but in any case it seems a reasonable ...
1
vote
1answer
131 views

Electric Potential at nano scale

I’ve a got a question; and I am hopeful that you can provide any information or direct me to a better resource. I'm not a physicist; so please correct me if I'm wrong. Scanning Probe Microscopy (SPM) ...
1
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1answer
284 views

gaussian fitting of xrd peaks

I am reading a paper regarding the nano crystalline material with hexagonal crystal structure. In that paper in order to find out lattice parameter of hexagonal crystal structure they have fitted a ...
1
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0answers
26 views

Radius dependence of Energy levels of spherical Quantum dots

I have frequently read in articles that the energy level of spherical quantum dots depends on radius. We simply match the wave functions inside and outside the particle and find the intersection of ...
1
vote
0answers
35 views

Why does matter behave differently in the nanoscale? [closed]

I know that materials behave differently in the nanoscale. One of the reasons that I have heard as to why this happens is due to the increased surface area of the atoms. But, are there other factors? ...
1
vote
0answers
43 views

Ballistic Conduction - Difference between Bosonic and Fermionic Transport

Ballistic Conduction is the phenomenon of an ideal conduction environment for quantum particles - for electrons the Ballistic Conduction is not infinity, but is proportional to the difference between ...
1
vote
1answer
73 views

One-dimensional (1D) CdSe nanostructures

I'm not a physicist, but I'm really interested in Nanotechnology. I've a question, and I hope that I can be provided by an answer. I was reading some articles about the one-dimensional CdSe ...
1
vote
1answer
111 views

What is surface plasmon of metal nanoparticles?

I really want to understand about the Surface Plasmon of metal nanoparticles, if anyone can explain it to me i'll be grateful. I have checked Wikipedia for it but didn't get anything clear.
1
vote
1answer
170 views

What kind of phases nanoparticles have (gas-solid-liquid)?

If a phase transition requires a number of particles that is in the TD-limit, can nanoparticles (~10 atoms) have phase transitions? What kind of phases and transitions nanoparticles have?
0
votes
3answers
52 views

Is duplication of nucleus, electron and proton (sub-atomic particles) possible? [on hold]

usually a single cell develops into a huge mass to form a substance or an organism. is this happening because of multiplication of sub-atomic particles? if yes, then is it possible to multiply the ...
0
votes
3answers
92 views

Do nanoscopes exist?

We are mostly all familiar with a microscope, and know that it helps to see MICRO components, like stuff that is photolithographically etched on silicon semiconductor die. (The latter can also be ...
0
votes
1answer
70 views

How long does it take to scan a typical scanning electron microscope image?

I suppose the answer depends on resolution and imaging area, but can you provide some ball park measures of imaging times with an SEM?
0
votes
1answer
103 views

Dopant Charge Transfer and Fermi Level shift

When a system has a dopant, how much does the Fermi level shift? For example, say a finite concentration of substitutional dopants replace some bulk atoms, and each has one extra electron. Ignore any ...
0
votes
0answers
22 views

Simple explanation on how to roll up a graphene sheet into a nanotube?

I have read some articles such as http://sinnott.mse.ufl.edu/Backgrounds/theo01_CNT.html and https://www.rose-hulman.edu/math/seminar/seminarfiles/2006-07/abstract2006-11-01.pdf which talk about how ...
0
votes
1answer
65 views

Is phosphorene a topological insulator?

All of the other "-ene" materials (silicene, germanene, stanene, and even graphene) are topological insulators. Phosphorene and these other materials all have honeycomb lattices and would appear to ...
0
votes
0answers
11 views

Zero field cooled / field cooled susceptibilities

I'm studying magnetic properties of nanoparticles in a liquid carrier and trying to understand better zero-field-cooled/field-cooled curves. We use the Stoner–Wohlfarth model and Chantrell ...
0
votes
0answers
14 views

Nanooptics microscopy limit

The limit of microscopes is 200nm, but apparently STED improves this according to this coverage of the Kavil prizes 2014 : http://www.photonics.com/Article.aspx?AID=56255 What is the current limit ...
0
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0answers
10 views

Impact of Ag nano-particle size on OPV efficiency : simulation

I would like to simulate the impact of gold nano particles size on the efficiency of Organic photovoltaic devices(inverted ofcourse) looking for any simulation plateform where this idea could be done ...
0
votes
0answers
17 views

Can unexposed PMMA be reused (successfully exposed) after development?

Can unexposed PMMA be reused (successfully exposed) after development? To clarify, PMMA is exposed using an electron beam in an SEM, and then the exposed areas are removed using a developer solution, ...
0
votes
1answer
94 views

Fermi Energy Variation

What would be a good Internet link that would properly explain Fermi Energy? How does the Fermi Energy of a material vary with external influence, such as doping of the material, and applied ...
0
votes
1answer
56 views

Estimating the number of atom/nuclei in a single quantum dot

I often read in introductions about quantum dots that depending on the fabrication method, a single dot contains about 100 - 100000 atoms. Assuming a self-assembled dot of lens or pyramid (cone) ...