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0answers
19 views

Phase Transition at Zero Temperature (Not QPT)

As is well known the Ising model exhibits a phase transition, except the one dimensional case in which the phase transition occurs strictly at $T=0$. Now I have always thought that this makes the case ...
1
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3answers
129 views

What are correlated magnetic moments?

My book has the following sentence and I don't understand what correlation or lack of correlation means: At high temperature the magnetic moments of adjacent atoms are uncorrelated (to maximize ...
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0answers
10 views

Regelation, ice cutting, and snowballs

Pressure decreases the melting point of ice, and applying pressure then releasing it will allow ice blocks to weld together by melting them and letting them freeze. See this video. The detractors of ...
3
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1answer
89 views

Simple estimation of the critical temperature of water

I'm trying to develop fermi estimation skills and I came up with a question for which I don't even know where to start from. Here goes: Is it possible to estimate the critical temperature (say in ...
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1answer
21 views

Bose-Einstein phase transition and average number of part in state l

The explanation I have trouble understanding is this: The average number of particles $<n_l>$ on state $l$ is $$<n_l>=\frac{z}{e^{\beta \epsilon_l}-z}$$ where $z=e^{\beta \mu '}$ is the ...
2
votes
2answers
157 views

Why isn't there an exponent in the free energy in Landau's quantum phase transition theory?

I have a question about Landau's theory of quantum phase transition. In his model, the free energy is assumed to be \begin{equation} F = f_0 + \alpha (T-T_c) \Delta^2 + \beta \Delta^4 ...
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0answers
48 views

How does one calculate the applied magnetic strength of a superconductor?

How does one calculate the applied magnetic strength of a superconductor? I spoke with a faculty member about this question. He explained to me that if one can break the spin pairing of two electrons ...
3
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1answer
337 views

Does a negative line tension in a 3-fluid immiscible interface make sense?

This question is inspired by this question/answer pair: Is this formula for the energy of a configuration of 3 fluids physically reasonable? Consider three immiscible fluids forming contact surfaces, ...
4
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1answer
153 views

Why doesn't topological phase transition break any symmetry? Hidden symmetry?

This question may be superficial. However why all people saying this without a proof? Just like the "hidden variables" assumption in quantum mechanics, can one disproof that there is no hidden ...
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3answers
1k views

Is there a phase transition between a gas and plasma?

Does a phase transition occur as a gas is heated to create a plasma? If so, is this a first or second order phase transition? Also, does the presence of a phase transition depend on the pressure or ...
6
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2answers
173 views

Why do phase transitions even exist? Why not smooth density change curves?

Why do phase transitions even exist? Why not smooth density change curves? What properties of matter, quantum or otherwise, predicts that matter will undergo phases at different pressures and ...
3
votes
1answer
46 views

How to quantify translational symmetry?

I'm trying to study phase transitions and I'm trying to find a way to classify regions of space based on their "crystallinity". I'm working with 3D coordinates, but I'll present the problem in 2D ...
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0answers
38 views

isochoric first-order transition

I wonder how can we classify a phase transition that occurs (at constant volume) without any discontinuity in pressure but with a step in energy? Is it still a first order transition?
0
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0answers
19 views

Vortex-domain wall co-excitation

Both vortices (or disclinations) and domain walls are possible topological defects in a spin system with frustration, but I did't find reference about the interaction of these two. Do any stackers ...
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1answer
36 views

NVT simulation of the phase transition

Why it is assumed to be incorrect to simulate,say, liquid-solid transition at constant volume (NVT simulation)?
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2answers
116 views

Why does a substance expands upon freezing? What conditions necessitate this?

Why does a substance expands upon freezing? What conditions necessitate this? For example, how does the slope of sublimation or fusion curve in a P-T diagram affect this?
0
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0answers
34 views

Is any phase associated with some fixed point in Renormalization Group?

In Wilson's paper I found a lot of discussion in expansions near a fixed point. He suggested that each fixed point is associated with a regime of the system. Like the fixed points of Anderson's Model, ...
3
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3answers
2k views

Freezing point depression - cooling my drink with the same method as salt on a highway?

I understand that adding/sprinkling, say NaCl, on a highway depresses the freezing point by making any moisture on the road harder to freeze as the NaCl molecules get in the way of phase transition. ...
2
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0answers
47 views

What is the physical mechanism of the topological phase transition driven by temperature?

The topological property of topological insulators (TIs) is characterized by the non-trivial topological invariants of their band structures, such as $Z_{2}$ topological invariants. While it's clearly ...
2
votes
1answer
971 views

What is solid- solid transformation?

I found this solid-solid transformation in wikipedia. http://en.wikipedia.org/wiki/Phase_transition#Types_of_phase_transition Please tell me what it is? It's present in types of phase transition in ...
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0answers
35 views

Example of critical (non-relativistic) quantum field theory in 1D?

Is there an example of a critical non-relativistic bosonic quantum field theory in 1D (no time)? So, the field theory can be describe by annihilation, $\psi(x)$, and creation operators, ...
4
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1answer
119 views

How does the notion of topological order relate to the Landau-Ginzburg theory of phase transitions?

As per Landau-Ginzburg (LG) theory, we write down a theory (Hamiltonian) with all possible interactions/operators (in terms of some order parameter) that respects certain symmetries. The ground state ...
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0answers
30 views

What is the different between topological order and Landau's order in a system

I have thought about topological order for a long time, but I am still confused it. Roughly speaking in my understanding, the topological state is the eigen-state of some special symmetry such time ...
2
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0answers
23 views

What material could be used to study magnetic phase transitions in a college laboratory exercise?

I am working to develop a simple laboratory exercise in solid state physics to be conducted by fourth year students of physics. The idea of the exercise is for the student to get some experience in ...
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1answer
62 views

Meaning of chemical equilibrium between two phases

Suppose two phases 1 and 2 of water, say ice and water, are kept in a closed container, at a fixed temperature $T$ and fixed pressure $P$? Then I have the following question: Is phase 1 in ...
1
vote
1answer
23 views

Must a symmetric phase and a symmetry-breaking phase be different?

When I was reading this paper, it urged me to ask whether a symmetric phase and a symmetry breaking phase must be different? As I am considering quantum phase transitions, let $H(g)$ be a general ...
0
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1answer
52 views

Concentration distribution in a phase separated mixture. Can't get the correct ODEs and boundary conditions

I wish to compute the equilibrium concentration distribution of a binary mixture that has phase separated. I start with writing the free energy as a functional depending of the concentration. I use ...
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1answer
32 views

Pressure and Phase Experiment Questions

Consider the experiment where a test tube filled with water is inverted in a beaker of water . (The following figures are not to scale of actual apparatus.) At time t=0, the instantaneous snapshot is ...
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0answers
31 views

How can we describe or model the spread of ice during the freezing of the surface of a still lake?

Premise: I live in a place where it is unquestionably wintertime in every aspect of the phrase. I was driving down the street and I drove by a lake. There was a recent and sudden temperature drop ...
0
votes
1answer
33 views

Metallic to insulating spin density wave transition in Hubbard model

For a half-filled Hubbard model with weak on-site Coulomb interaction ($U/t<<1$), it's quite intuitive that very likely the system will be in metallic phase. However, there is also such a ...
7
votes
1answer
219 views

Electric Field Change Freezing Temperature of Water?

I assume that the reason water freezes is because as you decrease the temperature, the kinetic energy of the water molecules decreases and the dipole bonding potential eventually over comes the escape ...
0
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1answer
32 views

find total change in temperature of a person being struck by lighning [closed]

A lightning flash releases about 1010J of electrical energy. If all this energy is added to 50 kg of water (the amount of water in a 165-lb person) at 37∘C, what are the final state and temperature ...
5
votes
1answer
255 views

Thermal AdS and the Hawking Page phase transition

I have some difficulty understanding the concept of pure thermal radiation, as described in Hawking and Page's paper on the Hawking-Page phase transition. The four-dimensional thermal AdS solution ...
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0answers
44 views

A question about Ising model

If $H$ is the Hamiltonian of an Ising model of $n$ spins on a lattice then is the following quantity look like something one has seen? $([uI-H]^{-1})_{ii} - \frac{1}{n}Tr[[uI - H]^{-1}]$ where $u$ ...
6
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1answer
89 views

How close to the critical point is sufficient close for measuring critical exponents?

I am learning Monte Carlo and just manage to simulate a phase transition by computing the heat capacity or the susceptibility. I wish I can also compute critical exponents.To this purpose, I have read ...
0
votes
1answer
209 views

Is An Exploding Beer Bottle An Accurate Simulation Of A “Frost Quake”?

A Frost Quake or Cryoseism is similar to an earthquake except it is triggered by ice expansion instead of tectonic activity. A Cryoseism may also refer to the sudden movement of a glacier, but I am ...
2
votes
1answer
118 views

How to calculate excluded volume in Onsager's hard-rod model?

Can somebody please provide a derivation of how to calculate excluded volume of two rods with angle of intersection being $\gamma$. rods are cylinders, capped with semi-spheres. Onsager theory of hard ...
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0answers
404 views

Can Lee-Yang zeros theorem account for triple point phase transition?

Now the prominent Lee-Yang theorem (or Physical Review 87, 410, 1952) has almost become a standard ingredient of any comprehensive statistical mechanics textbook. If the volume tends to infinity, ...
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2answers
448 views

Symmetry Breaking And Phase transition

Is every phase transition associated with a symmetry breaking? If yes, what is the symmetry that a gaseous phase have but the liquid phase does not? What is the extra symmetry that normal $\bf He$ ...
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1answer
40 views

Deconfinement at high T $\leftrightarrow$ spontaneous breaking of the center of the gauge group

I am reading Witten's "Anti-de Sitter Space, Thermal Phase Transitions, And Confinement In Gauge Theories" (see here), in which he connects the confinement-deconfinement transition in $\mathcal{N}=4$ ...
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2answers
474 views

The thermodynamics of heating water in a rigid container

When the pressure on the liquid surface is less than the vapor pressure of the liquid at a given temperature, the liquid will start to evaporate. This is common sense. The problem is more difficult ...
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1answer
43 views

Does Nucleation Occur during Phase Equilibrium?

I understand that during phase transition nucleation must occur. I'm wondering, once phase equilibrium is established, does nucleation still occur? For instance, in liquid-vapour equilibrium, does ...
0
votes
1answer
50 views

Confusion about the Definition of Boiling Point

From the description of boiling here: Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the ...
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votes
0answers
17 views

Weight of a material

I'm dealing with a problem here. Does a material lose weight when it transforms from solid to liquid? I believe it does. It loses weight because some of it becomes gas. Can anyone help me? Thank ...
0
votes
1answer
24 views

Orienational order parameter in isotropic systems

I have what may be a dummy question. In NMR or in the study of liquid crystals for example, an order parameter $S$ is often used: $$ S=\left\langle\frac{1}{2}\left(3\cos^2\theta−1\right)\right\rangle ...
0
votes
1answer
49 views

Freezing or melting Brine

In the freezing of brine, is it possible to do it at a rater or in such a way that the water only freezes or the ice is somehow isolated? Or conversely is this possible in the melting of brine-ice?
5
votes
2answers
976 views

What causes a Phase-Transition?

A phase transition occurs when for example, heat is applied continuously to a liquid and after a certain time it converts into a gas. How does this process work in detail? Is their a chain reaction ...
2
votes
1answer
52 views

Question Regarding Nucleation in Phase Change

When liquid turns into solid a nucleus is required. Is the same requirement present for solid-liquid (melting)? Do condensation also require nucleation sites like in freezing? When I look at ...
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0answers
28 views

Mean-field approach to quantum phase transitions in Fermi systems

I have a basic confusion concerning the mean-field theory of quantum phase transitions in Fermi systems. Consider as an example the BCS theory of superconductivity in a Dirac fermion system, ...
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0answers
18 views

dynamic structure factor for nucleation

I know that using the peak position/moment of structure factor or may be by first zero or minimum of pair correlation function we can estimate the characteristic length scale in a phase separating ...