Why topological insulator (TIs) AFM image show triangular shape terrace while unitcell is hexagonal?

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What is the difference between the band structures plotted as E vs k (-pi/a to +pi/a) and E vs k (where k is from M to K or K' edge of brillouin zone?

I know that when we plot band structure i.e E vs. k, the shape is parabolic. But when we plot band structure for E vs k, where k is different points (gamma, M, K or K') of Brillouin zone edge...

06 July 2019 1,023 3 View

What is the concept of wave-packet?

I know that wave-packet is the super-imposed form of the waves. It is created when some waves have interference and a particle (say electron) can be represented by a wave-packet. I am bit confused...

06 July 2019 9,600 34 View

What is the physical significance and consequence of zero density of states at Dirac point in Graphene or Topological Insulators?

Generally we say that the density of states (DOS) at Fermi level contribute to many phenomenon. However in the Dirac cone DOS is zero at Fermi level. What does it mean and what are its...

06 July 2019 7,426 4 View

Why molecular beam epitaxy (MBE) is not called atomic beam epitaxy and how it differes from sputtering in growth sense?

Why molecular beam epitaxy (MBE) is not called atomic beam epitaxy and how it differs from sputtering in growth sense? Can one grow sample in sputtering instead of MBE without changing any growth?...

03 April 2019 8,240 10 View

Why holes effective mass and mobility are higher than electron's?

electron and hole effective mass

01 February 2019 7,785 5 View

Is oxidation reversible process?

Can an oxidized thin film sample get de-oxidized if put in the vacuum?

31 December 2018 8,179 14 View

Why do we call spin momentum locking in graphene as Psuedo spin-momentum locking?

why in case of Graphene and other 2D materials spin is called as psuedospin? and how to we get other degree of freedom called valley degree of freedom? Please give simple explanation! Thank you

09 October 2018 6,851 3 View

What is physical interpretation of activation energy in metals and semiconductors transport?

What is physical meaning of activation energy? I know that the activation energy can be estimated by Arrhenius equation. It has been observed that the activation energy is usually less than the...

09 October 2018 4,288 5 View

How to etch TGMR resist (-ve type)?

Can someone help me in etching TGMR? I try chemical etching but not able to etch it. Is there another way?

06 July 2018 9,649 1 View

Why magnetoresistance increases when magnetization is in the direction of current flow?

It was seen that when magnetization is in the direction of current flow, resistance is minimum and vice versa. Why resistance increases when spins are aligned and why it decreases when spins are...

10 November 2017 4,905 7 View

Physics: Why do we describe light by referring to its wavelength, but microwaves and radar pulses by referring to their frequency?

In physics, the description of the properties of light generally refers to its wavelength (nm), while in the range of microwaves and radio waves we refer to the frequency of a signal (e.g. kHz or...

03 March 2021 1,682 3 View

I need to image mesoporous silica nanoparticles that are in ~100 nm size and do high resolution TEM to look at mesopores. what grids should I use?

Need to image mesoporous silica nanoparticles using the TEM. Also, need high resolution TEM images to see the mesoporous structure. Kindly suggest what kind of grids to use. Thanks, Shatadru

02 March 2021 1,787 2 View

Why are the velocities so high in my Boussinesq approximation Fluent simulation?

Hello, I have a mechanism where air rises due to convective flows. In this simulation, nothing is driving the air except this. I understand that the Boussinesq approximation only works for small...

02 March 2021 4,910 3 View

12% ledeburitic cold work tool steel, etched for revealing retained austenite, any help for clarifying?

Hello everyone. Given microstructure image belongs to a 12% ledeburitic cold work tool steel (annealed and tempered). The sample was etched with picral (100 mL ethanol and 4 g picric acid). I...

02 March 2021 4,119 3 View

Is There Any Feasible Method To Test Fluorescent Compounds Other Than Fluorescence Spectrometers ??

Is There Any Feasible Method To Test The Efficiency Of Fluorescent Compounds Other Than UV Spectrometers ? Suggestions Would Be Appreciated !

02 March 2021 5,785 3 View

Why almost every element would be metallized in sufficiently high pressure and low temperature?

(This statement is from wikipedia, BTW). What is so special about metallic bond that is limiting high-P low-T state of a matter (as long as individual atoms exist, not white dwarf of neutron star...

02 March 2021 3,309 2 View

How Relativistic effects is one reason for lanthanide contraction?

The Lanthanide contraction which is the decrease in ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, is due to poor shielding of the 4f...

01 March 2021 2,272 4 View

Shall I skip the measurement model in SmartPLS?

Hello everyone, I had run a mediation model in SmartPLS using questionnaires that were already validated among my statistical population. A professor who edited my paper -though she is not...

01 March 2021 3,052 3 View

In Molecular Dynamics Simulation, how do I make changes to the force field according to my protein?

Hi In Molecular Dynamics Simulation, how do I make changes to the force field according to my protein? I got this error in the add-ion stage: Fatal error "./ amber99sb-ildn-HHH.ff / force...

01 March 2021 8,747 4 View

What is the state of the drug inside solid lipid nanoparticles (SLNs)?

I am a little confuse with the mechanism of solid lipid nanoparticles (SLNs). The main point of encapsulating drugs into SLNs is because some drugs have low solubility in water. Therefore, SLNs...

01 March 2021 3,703 3 View