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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5answers
2k 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 ...
8
votes
0answers
381 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
votes
1answer
454 views

Have they really photographed light behaving both as a particle and a wave?

I just came across this article where they are claiming that they have photographed light behaving both as a wave and a particle! The paper has been published in Nature Communications and I read the ...
7
votes
2answers
111 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
votes
5answers
1k views

Nano-particle or Molecule?

What's the difference between something being labeled a "nano-particle" or it being called a "molecule"?
6
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1answer
542 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 ...
5
votes
2answers
580 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 ...
5
votes
1answer
315 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
2answers
1k 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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3answers
787 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
2answers
76 views

Could a long carbon nanotube be broken by hand?

Assuming we could get a single nanotube a metre long, would it be possible to break it by hand or would it slice through just about everything including flesh and bone? Could we even grip it, or would ...
4
votes
3answers
154 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 ...
4
votes
1answer
462 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
2answers
95 views

Can there be a string so thin as to be invisible, but that can still support a visible weight?

A spider web thread is very thin, yet it can support a spider. Given that the human eye visual acuity is finite, are there materials, natural or man-made, sufficiently thin that a string made from ...
3
votes
1answer
813 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
493 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
4answers
204 views

Can a single molecule have a state?

I was studying a book about thermodynamics of nanosystems and I got stuck with this question in my mind which I couldn't find an answer for. For instance, does a single water molecule have a state, ...
3
votes
1answer
98 views

Specific Heat of Nano Particles

Specific heat of nano particles is less than bulk specific heat of them. Why?
3
votes
2answers
286 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
votes
1answer
264 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
106 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
4k 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
524 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 ...
2
votes
1answer
42 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
votes
2answers
45 views

How can you add an exactly one-atom-height layer upon your material?

So for example let's say I have a 2cm x 2cm x 2cm cube of gold powder. Now I want to add just another layer of 2cm x 2cm x 1 atom upon it. It's been a long time since I last read some physics but I ...
2
votes
2answers
49 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
votes
1answer
76 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
1k 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
votes
1answer
76 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 ...
2
votes
1answer
49 views

Au, Ag nanoparticles plasmon peak position?

Is the interaction between metallic nanoparticles (~ 20 nm) and light in the UV-Vis-NIR range governed by Mie theory or by Rayleigh scattering theory? Where are the Au and Ag plasmonic peaks located? ...
2
votes
0answers
101 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
votes
0answers
248 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 ...
1
vote
1answer
3k 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 ...
1
vote
4answers
225 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? ...
1
vote
2answers
124 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
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2answers
209 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
123 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
253 views

How to calculate the differential scattering cross section?

I am doing some simulations with the Meep code to study some properties of a metal nanoparticle. The situation is this: an incident electromagnetic wave on a metal nanoparticle. By now I know how to ...
1
vote
1answer
137 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
vote
1answer
520 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
vote
0answers
31 views

Fresnel equations of S and T waves and Isofrequecy Curves: Feeling confused

First of all sorry for my (probably) bad english. I've been studying propagation of light in anisotropic media from the Born and Wolf and from Landau "electrodynamics in continuous media" and I'm ...
1
vote
0answers
23 views

How come plasmon resonances of metals are capable of being tuned to different wavelengths?

I read in this article that plasmon resonances though being a pre-determined property of a metal are capable of being tuned to other wavelengths when these same metals are made into tiny ...
1
vote
2answers
56 views

Software for analysing SEM or TEM images

I am looking for a software to analyse SEM and TEM images of some PLD experiments because I want to characterize the samples, like calculate the concentration of nanoparticles, size, and do some ...
1
vote
0answers
69 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
1answer
22 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 ...
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0answers
75 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
48 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
125 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
192 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
145 views

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

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 ...