Phase transition Definition and 51 Threads

Hello, I'm a highschool student and there has been this question bugging me ever since my physics teacher insisted my point of view was wrong but it never sat right with me so I want to share it and get a proper explanation. Consider a perfectly isolated system containing an infinite mass of...

I am trying to reproduce the results from this paper where they find out the expression for the Landau functional to be $$\psi(x,t,p)=\frac{1}{4}(\frac{1}{x}+6x+px^3-4tx^2)$$ We plot the Landau functional v/s the order parameter($x$) at $p=0.5$ and obtain the Figure 4. from the paper as Now...

Physicist Grigory Volovik has put forward some ideas about the universe undergoing a topological phase transition (especially in the early stages of the universe). He published a book called "*The Universe in a Helium Droplet*" where he explained his ideas. You can find a brief discussion here...

So for part a, I separately minimized F wrt ##\theta## and ##P## and got the following. $$\frac {\partial f} {\partial \theta} = a_{\theta}(T-T_{\theta})\theta + b_{\theta}\theta^3 - tP = 0$$ $$ \frac {\partial f} {\partial P} = \alpha(T-T_P)P -t\theta$$ $$ P = t\theta \alpha (T-T_P) $$ Then...

Trying to understand what the math methods are exist to determine quantum phase transition and how I can calculate it, by what methods.

I am looking for possible examples and a variant of Landau's theory of phase transitions for an exotic order-disorder phase transition, in which a thermodynamic system jumps into a disordered (or less orderly) state by reaching the maximum critical value of the order parameter. That is, in one...

How is it proved that Van Der Waals gas is a second order phase transition? The second order derivative of the pressure (P ) with respect to volume ( V ) don't have a discontinuity ( except at point V = Nb , but the pressure is not existent for V<=Nb ). So how come Van der waals gas describes...

Not sure where to actually start. Do I need to do a virial expansion? Any tips on on where to start would be greatly appreciated.

Is atomic electron transition a phase transition? https://en.m.wikipedia.org/wiki/Atomic_electron_transition

I actually can't figure out what kind of phase transition it is and how to proceed through..!

I did the first part using the transfer matrix method: $$ Z = Tr(T^{N}) $$ In this case, the transfer matrix will be $$ T(i,i') = \begin{pmatrix} e^{\beta J} & 1 & e^{-\beta J}\\ 1 &1 &1 \\ e^{-\beta J} & 1 & e^{\beta J} \end{pmatrix} $$ To get the trace of $T^N$, you find the...

hello everybody does always phase undergoes transition when a pressure applied on a crystal ?even when the temperature is constant? and can pressure be increased without increasing temperature for a crystal? best regards Nawzad

Homework Statement Prove the following relation for which clausius equation holds : Cs=Cp-αV(ΔH/ΔV) Where Cs=∂q/∂T at constant S and is the heat capacity in the coexistence line of 2 phases Homework Equations dq=dU+dW dP/dT=ΔH/(ΔV*T) The Attempt at a Solution I do not fully understand why q...

Hello everybody. I am trying to understand better what happens at a liquid-gas phase transition for the Van Der Waals model. From what I have understood, from the Van Der Waals model we are able to plot the curve P(V) and to calculate the free energy F. Here are such curves : Then, we...

Hello, I have heard that one of most acceptable theory (or hypothesis) describing the inflation phase of universe is that energy to this stage is drawn from phase transition when strong interaction is separated from "preinteraction" (when all interactions were undistinguishable) Do you agree...

There's something that has been bugging me for over a year now and I seem to be unable to find the answer. I would appreciate it very much if somebody could help me out. The thing is that I don't understand how it is possible that in second order phase transitions the correlation legth becomes...

Hello everyone, I'm doing revision for a final exam in Thermodynamics and i found this exercise i can't solve: A particular material has a latent heat of vaporization Δh, constant along the coexistence curve. One mole of this material exists in two.phase (liquid-vapor) equilibrium in a...

There is a question that has been bugging and puzzling me for a long time and I wondered if somebody could help me to figure out what the answer is or where I am not thinking straight. Let us assume that the standard model of particle physics is more "right" than "wrong" and there is no such a...

There's something that I'd like to know and haven't been able to find in any book: 1.- Is the number of second order phase transition university classes known? 2.- Do we know quantitatively know the behavior of all such second order phase transition university classes? 3.- Do we know the...

A very neat video showing a phase transition in rotating balls in a cup. Serves as a good analogy to other phase transions.

I suppose that my questions are pretty basic, but I've been trying to find out the answers and not succeeded. 1.- Do cosmologists really think that the vacuum state suddenly changed in the early Universe? If so, would it be like a phase transition? If so, first or second orther? 2.- Does the...

The reason I ask is that the singularity involves a region of spacetime composed of a different order of magnitude than i suppose the region outside the singularity.

I heard of it several times in colloquiums. But I still cannot grasp the meaning. What is the control parameter in this phase transition?

Hi,I'm new here, and created my account solely for following question: Does the incompatibility between QM and Relativity indicate a phase transition at high energies? (as in: indicate more than a "could be")

Homework Statement [/B] Hi there! This is a question from a practice problem sheet I got from the lecturer of my Condensed Matter 1 course. Below are the normal vectors to the {111} and {112} lattice planes: Homework Equations [/B] Bragg Condition: \begin{equation} n \lambda = d \sin...

The wikipedia article mentions that the model allows for "phase transitions" but doesn't specify what it means by this? What is a phase transition in the context of an ising spin glass? Is it when the mathematical model of a magnet, changes from solid to liquid? In this paper...

At first, we need some state parameters(like P/T/V) to fully describe a system. And the order parameter is also a parameter which could describe the property of the system. However, in the Laudau theory, why it said that order parameter is an external parameter(not a independent variable)? Is...

I have just been reading a classical paper on the formation of majorana edge states (MES) in quantum wires. The hamiltonian is Kitaev type with a superconducting and spin-orbit interacting and one finds that the energies have a gap that closes and reopens as we vary the magnetic field. According...

Hi I'm trying to use Peierl's argument which in essence is clear to prove that there does exist a phase transition in the 2D Ising model without external field. The issue I'm having is of a more mathematical nature, in class it was mentioned that there is a phase transition if for some ##\delta...

Hello Community! I can't find a good answer(if there is) to my question. When in statistical mechanics we can define the order parameter for to study some phase transition. we need to define a order parameter. Now, I want to know if we can to define/find some "order parameter" for to...

Hello, Wikipedia states: Phase changes, such as melting or evaporation, are also isothermal processes. I am interested in calculating the enthalpy of a given phase transition. If the process is isothermal, I would immediately say that H is 0, according to the following equation: dH=CpdT...

So a phase transition occurs when a system may minimize its free energy by spontanously breaking some symmetry. At least that is what I have learned from my current course so far. However I also did another course concerning phase transitions. In this case phase transitions were always...

Homework Statement There is a solid that can be in two phases, with energies U1(S,V) = S2/a1 + b1V(V-2Vo) and U2(S,V) = S2/a2 + b2V(V-2Vo). Consider a phase transition between the two phases at zero pressure. At what temperature, T0, does it occur? Homework Equations T = ∂G/∂S...

I have a problem in finding the heat transfer coefficient of a heat exchanger in which Ethane undergoes a phase transition. I would like to find the Prandtl number of Ethane in the phase transition region. So far I thought I would use the following: Pr_av = x * Pr_g + (1-x) Pr_l Pr_av =...

Homework Statement http://icho2013.chem.msu.ru/materials/IChO-2013_Theoretical_Official_English_Version.pdf Looking at problem 1. Homework Equations The integrated form of the Clausius-Clapeyron equation: ln(\frac{P_{T2}}{P_{T1}}) = -\frac{\Delta H}{R} \cdot (\frac{1}{T_2} -...

Hi, I'm Teemu from Finland, and I'm just getting my master's degree in physics completed (only one course in electronics left). This is my first post in Physicsforums. I was thinking about a problem in statistical mechanics. As you all know, if we have a one- particle system where the...

As a material is heated, it increases in temperature until it enters a phase transition. During the transition, added heat does not increase the temperature. As this heat is being added, what is the substance? Is it a mixture of liquid and gas perhaps? If so, what are the proportions? In...

I just watched a video of James Gates and he discussed something he called the Gross Perrywall phase transition. It was named after David Gross, I am assuming most of you are familiar with his work. In an attempt to search more about this I came up empty. I do not know if I am spelling it...

Hello, I ask for your help because I can't find any information about Earth crust-atmosphere phase transition. I noticed indeed that our feet tread upon a solid surface, while our nostrils breath a gazeous compound ! This remark seems so obvious that I can't find any description neither...

This is from Krauss' A Universe from Nothing: It seems like he's saying that before inflation kicked in around 10^-36 or 10^-34 I forget which that the universe, I'm guessing from 10^-43 - 10^-36 was in some sort of false vacuum state, analogous to the way matter changes phase from gas to...

Is anyone familiar with this or heard of this concept before? It started in 1953 by a paper by Dicke published in peer reviewed Physical Review Journal called "Coherence in Spontaneous Radiation Processes" http://prola.aps.org/abstract/PR/v93/i1/p99_1 Then in 1973 Hepp and Lieb published...

Dear Members, I am strugling with calculations on rapid phase transition (RPT) of CO2 in a high pressure vessel. I looked everywhere, from isochoric data to ...you name it but can't get there... The question: What will the resultant pressure be when solid or liquid CO2 in area A contacts...

Hi, I was listening to Susskind's lecture on statistical mechanics (lecture 8). He mentioned in relation to Ising model of magnetized spin systems that there could not be any phase transitions in one dimensions. He mentioned that it has to do with the stability of the system. Can anybody...

More specifically, consider a Hamiltonian with a changeable parameter a. When changing a, the ground state of the system will change. In some cases, one phase crossovers to another, like in other cases, there's a phase transition. What factor determines the difference? Actually I am now working...

I am looking at some of the notes but don't quite understand this. What are the physical explanation of the graphs (Fig 4(a) and 4(b)) on Page 4 ? http://www.pma.caltech.edu/~mcc/Ph127/b/Lecture3.pdf" Why V_{g} decreases with temperature but V_{l} increases with temperature?

Homework Statement Give the physical explanation of the graphs (Fig 4(a) and 4(b)) on Page 4 http://www.pma.caltech.edu/~mcc/Ph127/b/Lecture3.pdf" Homework Equations 1) Why V_{g} decreases with temperature but V_{l} increases with temperature 2) Why must phase transition happen at...

can anybody tell me why in general phase transition is not possible in one dimension? and for a lattice gas at low temp. why it requires long range order to occur phase transition?

Hi! I read in Zinn-Justin, that first order phase transitions always have a finite correlation length. Since correlation length is the inverse of the smallest physical mass within a model, this would mean that there can be no Goldstone bosons for a 1st order phase transition. How can that be...

hi, I find that the point where the entalphy vs pressure curves of diferent phases crystaline of material is crossing corresponding at the presure where occurs a phase transition, also i find that by meant of the solope of the tangent of the curves of energy vs volume i can determine the...

Hi, I was wondering, what actually are phase transitions such as fusion or evaporation? I know thermodynamic definitions such as points where the Gibbs energy is non-analytic or heat capacity changes abruptly, but these say nothing about mechanism. Why does a substance suddenly change its...