Condensed matter Definition and 176 Threads

How can I see, by looking at a band structure if the substance in question can be viewed as a free electron gas (FEG) or not? What characterizes a FEG in a bandstructure plot? Thanks in advance!

Hello, I am currently struggling to understand how one can write a Hamiltonian using group theory and change its form according to the symmetry of the system that is considered. The main issue is of course that I have no real experience in using group theory. So to make my question a bit less...

Hi! I never really understood band structure diagrams. I think they represent the energy of an electron, with the given circumstances, at a k vector. Are the electrons only allowed to be on the lines here? Or can they also be in areas enclosed under/between certain lines? What are some...

what are the good books on advanced condensed matter physics with detail notation explained?

I have read that postdocs are extremely hard to come by in Astrophysics, and is likely a dead end at the end of the PHD and that Condensed Matter is less competitive in academia. Would a Condensed Matter PhD also provide more opportunities in UK science industry - in particular the life sciences...

Hi, I'm an undergrad materials engineering student. I am thinking of studying all the way to a PhD as I'm interested on working in research. Right now I work with Semiconductors and I like the field a lot. However, considering what I'm studying, I want to know if it's a good Idea to look for a...

Quantum field theory is a powerful tool to calculate observables given the amplitude of some process. I only know the application to high energy physics: you have a Lagrangian with an interaction term between some fields, and you can calculate the amplitude of some process. Once you have this...

Hey, I am currently busy with studying solid state physics and looking at diffraction theory. Following link explains Frauenhofer diffraction pretty good: http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/mulslid.html#c3 Let's assume a N=6 multiple slits. Its diffraction pattern depends on slit...

hello all i am a new member on Physics Forum i am a last year master student in fundamental physics ( again ) and also have done a master in condense mater and nano-science i worked on noble solid /amorphous interface in my first master internship ( DFT and ab initio molecular dynamic using...

I've learned that in a crystal, the crystal momentum is conserved. When one considers the electrons as Bloch waves, they have a momentum that doesn't commute with the Hamiltonian and they have well definite energies, hence they cannot have a well definite momentum, because there is no basis in...

Hello! I want to know how does a parity transformation affect Bloch states! I always knew that parity takes the position vector to minus itself (in odd number of dimensions), but I have read that it also takes the Bloch wave vector to minus itself but I have not found a satisfactory proof of...

Consider a solid material such as a conductor. I would like to know if there are ways to determine the voltage at specific spots on the material, without plugging a metallic wire and connect it to a voltmeter. I know voltage is relative and I'm interested in checking voltage differences across...

I was wondering what the difference was between the valence band and fermi level? How do we distinguish between the two? Thanks in advance.

I did research on theoretical formulations in general relativity during my MSc studies. I look forward to pursuing PhD and have searched many universities and some research institutes for suitable research themes, but haven't found many research groups undertaking research consistent with my...

The Hamiltonian of the Qi, Wu, Zhang model is given by(in momentum space): ## H(\vec{k})=(sink_x) \sigma_{x}+(sink_y) \sigma_{y}+(m+cosk_x+cosk_y)\sigma_{z} ## . What is the physical meaning of each component of this Hamiltonian? Note: for the real space Hamiltonian(where maybe the analysis of...

I am leaning the Haldane model : https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.61.2015 Haldane imaged threading magnetic flux though a graphene sheet, and the net flux of a unit cell is zero. He argued that since the loop integral ##\exp [ie/\hbar \oint {A \cdot dr} ]## along a path...

Hi, I'm currently in my last year of undergrad and I'm wondering about which specialization I should pursue. I'm looking for career stability, I don't mind leaving academia I'd just like to employ what I study in school in my future career. So, to my questions 1) In terms of career stability...

I am wondering if there is some type of matter in the core of the Black Hole. Is it possible to compute the distance from the surface of the Black Hole Core to the Event Horizon? Oh that would be fun to calculate.

I'm currently working in condensed matter theory. Looking at other fields of physics, it seems easy to relate them to a lay audience; for example, in explaining why you study physics, a high energy physicist could go on about the 4 fundamental forces and searches for a unifying theory of...

\bf{Setup} Hi! I am trying to derive the wavefunctions of the zero energy solutions of the Schrodinger equation in a 1D p-wave superconductor (Kitaev model). I am starting with the Hamiltonian $$ \begin{equation} H = \left[\begin{array}{cc} \epsilon_k & \Delta^{\ast}_k\\ \Delta_k & -\epsilon_k...

Hi All, I needed some help or guidance starting my MSc reading, as there is tonnes of literature out there and it's difficult to understand what is necessary. I am beginning to look at applying screening models to a 2D system, such as the Thomas-Fermi continuum screening model, to a 2D system...

(Mentor note: moved here from noon homework thread hence no template) I was studying vibration of a one-dimensional monatomic chain and the textbook used periodic boundary condition (PBC). I wanted to justify the use of PBC, so I came up with this: atoms deep inside the crystal sees an...

Nobel laureate Alexei Abrikosov, a condensed matter theorist, passed away yesterday. I have no additional information at this time.

Hi! I'm trying to show how the chemical potential depends on the temperature and I'm advised to use the Sommerfeld expansion. I'm using it on the density of charge n=\int^{+\infty}_{-\infty} \rho(\epsilon)n_Fd\epsilon , which gives n=\int^{\mu}_{0} \rho(\epsilon)d\epsilon...

According to the quantum mechanical free electron model the average energy is E=3EF/5 for the 3D case. Nevertheless I saw in a specialised physics book that for the 1D model the average energy at T=0 is 0 and wanted to know if it is the same for the 3D case.

Can anyone suggest some books which deals with electron correlations in many body systems?The book should cover second quantization,hubbard model,mott transition etc.I'm a beginner in this filed and want to learn from the very basics.

Hi everyone, Currently, I am self-learning Renormalization and its application to PDEs, nonequilibrium statistical mechanics and also condensed matter. One particularly problem I face is on the conservation of symmetry of hamiltonian during renormalization. Normally renormalization of...

Hi. I'll be doing a master's degree in nanophysics and working on electron transport in arrays of qubits. I don't know anything (or barely) about the second quantization and would like a book which covers it, and on condensed matter overall. So far I've been told about Bruus&Flensberg's...

I'm a bachelor student in Physics and I would like to continue with a MSc in the field of Condensed Matter Physics. I have to choose between some courses at my university and, since I'm not already an expert in Condensed Matter I would like to have a suggestion. If you were in my situation and...

I've been recently trying to understand the concept of paramagnetism, but I feel like I'm running into 2 conflicting models. Stern–Gerlach seems to suggest that electron spins always point up or down to an incident magnetic field, regardless of their spatial orientation. Similarly, when...

How is a top gate used to change electron density in 2D semi conductors? I get the principle, you are just shifting the chemical potential by some voltage so that there are more or less electrons in the specific bands. But how is it physically done? Thanks.

What extra math courses should an undergrad take (or self-study) if they want to go into Quantum Optics or Condensed Matter theory? I've already taken calculus, linear algebra, ODEs, PDEs, and complex analysis (I will also be doing a second course on linear algebra in two months time).

Hello, This problem is about cooper pair formation and what happens with the calculations if there is an attractive potential between electrons but it is not in the presence of a filled fermi surface. 1. Homework Statement Two electrons just above the filled Fermi Surface of a material can...

Suppose I have an n-doped semiconductor and want to measure the electron concentration in the conduction band as a function of temperature. How would I go about doing this by measuring the Hall coefficient as a function of temperature, given that I don't know the electron and hole mobilities...

Can you give the name of an excited book of solid state / condensed matter physics ( beside kittel and ashcroft ) ? a book than contains more talking about experimental rather than theory

It is said phonon(not photon) in superfluid experiments could also produce similar upper-limit speed effect which I'm not sure if that's also Lorentz invariant. Another problem is that I can't dig out those paper that demonstrates this kind of effect. Anyone ever seen any of this paper? Thanks..

What are prerequisite courses/topics to better understand holography as applied to strongly correlated condensed matter systems? Any references/textbooks would be appreciated. I'm doing research on this topic and would like my understanding to improve. Thanks very much

Homework Statement *This is not my whole problem, I am only stuck on how to interpret one part of the question. Put simply, I want to find the expression for the density of energy levels in a given energy band per unit volume (in some crystal structure). Say I have an infinitesimal interval of...

Hello, So before I start, I realize that this question has been asked in the past, but all of the threads were over several years old so I'm not sure if the information is still current. I've been thinking about this decision for a while: I'm currently in my second year at a respected...

Hello all! I am second year undergrad at a university in US. I planned to major in chemistry and took five chemistry classes (organic and inorganic) and worked at an organic chemistry lab in my first year, but didn't really like it. After searching through all areas in chemistry and physics, I...

My question is a little general, and that is how we say that a system is a critical system? for example the transverse Ising model is a critical system? I think the answer is yes, since as we change the transverse field we see that there is a phase transition between ferromagnet and paramagnet...

Could someone tell me about what I must have as a knowledge to study condensed matter physics ?

What is the best book that gives you the essential knowledge for condensed matter physics ?

I have just been accepted to pursue an advanced degree (Masters) in Physics with a specialization in condensed matter. I have some questions regarding this field (Google results are somewhat outdated). (1) What exactly does a condensed matter physicist study? I know it is the study of...

Homework Statement So I'm given a spin 1/2 particle in a rotating magnetic field in the (x,y) direction and a constant field, B_0, in the z direction and am asked to find the S matrix describing it. Given is: B(t) = [B_1 \cos(\omega t), B_1 \sin(\omega t), B_0] Homework Equations H = \sum...

Why can not the density of states of a metal at Fermi level be zero? Thanks!

I'm working through a derivation of the [Kohn Effect](http://en.wikipedia.org/wiki/Kohn_effect), as presented in Ziman's 'Principles of the Theory of Solids.' However, I find myself getting a somewhat different result. The book states that calculating $$\epsilon(\mathbf{q}, \omega) = 1+...

Hi PF Family, I'm a rising junior majoring in physics. I plan to enroll and be accepted into graduate school(s) such as UIUC, Princeton, and MIT. I know that requires much work and hard work. However, my problem is in choosing the right program. I want to be able to integrate CMP and Materials...

Hi all again, I started a post earlier and it was buried somewhere by now. I really need more input and information and hope you all can help. How are admission process different, CM vs MS&E? CM belongs to Physics department while MS&E is usually on the engineering side. I got my Physics...

Hi everyone! I was admitted as an undergraduate transfer student to MIT and Harvard College for Fall 2015. I am now stuck deciding between the two. Which one do you think is better for studying experimental condensed matter physics or just physics in general?