State Definition and 1000 Threads

When i take a coherent state ##|\alpha>## if ##\alpha -> 0## then the limit is the Fock state for n = 0. so ##|n = 0> = |\alpha = 0>## The problem is that they seem to have different http://www.iqst.ca/quantech/wiggalery.php: Where is the error? Thanks. Edit sorry, in the link the W function is...

Homework Statement 1 kg air at the pressure ##10^6##Pa and the temperature ##125^\circ C = 398K## expand until the volume is 5 times larger. The expansion is done with change in heat at every moment being ##1/4## of the work done by the gas. Calculate the end pressure.Homework Equations ##dU...

Homework Statement [/B] The photo included provides the problem but the professor stated that the right side source is supposed to be 100t and not 80t. The problem wasn't printed correctly in the book so I assume the solution wasn't either. The solution via the book is v1=2.56cos(100t+139.2°)...

Can you please explain to me this statement The farther an electron is from the nucleus, the higher is the energy state, and any electron that has left its parent atom has a higher energy state than any electron in the atomic structure. And is the meaning of electron state.

Hello I am trying to learn about the change of state between solids, liquids and gases but I don't understand exactly how it works. I've been reading material given by my school, but I got these two questions to ask because I can't answer them. These are not questions on the sheet they just...

I have created an initial state code with perodic boundary conditions and normal distribution of velocities. I not know where is the problem, when I compile the computer detect the 112 error. Could anyone help me please? Thanks! the code is...

Homework Statement For some applications it is important to minimize the temperature dependence of electronic components. For example, there is a special alloy called constantan that can be used for temperature independent resistance elements. Do you expect constantan to have a high or low...

Homework Statement Show that the coefficient of volume expansion can be expressed as β= -1÷ρ (∂ρ÷∂T) keeping P (pressure) constant Where rho is the density T is Temperature Homework Equations 1/v =ρ β= 1/v (∂v÷∂T) keeping P (pressure ) constant The Attempt at a Solution I started with...

Hey everybody, I am looking to solicit some information from those who might know. I have been poking around here to see what its like for an undergrad to possibly apply to UK grad schools for physics, and all the posts I find give the answer 'not good.' I was wondering if it is still like it...

As far as I understand, the Hilbert space formalism can be derived using functional analysis and representation theory (not familiar with those) from the requirement that observables (their mathematical models) form a C*-algebra and the possible states of a system map the members of the algebra...

Hello! If we consider a single-particle system, I understand that the measurement of an observable on this system will collapse the wave function of the system onto an eigenstate of the (observable) operator. Therefore, we know the state of the system immediately after the measurement. But as...

Hey guys, I got accepted to a few Cal State Computer Science masters (MS) programs (I live 10 minutes from one of them). I also applied to UC Davis and UC Irvine for their BS in Computer Science (would be a 2nd bach. degree, first was Psychology, pre-req's done/am doing at a CC), and am waiting...

Homework Statement Let ##h## be the height above sea level. Show that the reduction in air pressure ##dp## as a function of ##dh## is given by ##\frac{dp}{p} = -\frac{Mg}{RT}dh##. Where ##M## is the molar mass of air and ##T## the temperature at height ##h##. 2. Solution This problem got a...

For a steady state current, is ##\frac{dI}{dt}=0## or is ##\frac{\partial I}{\partial t} = 0##?

Why each energy state is having only 1 Fermion or electron instead of 2? as we know fermions or electrons obey pauli's exclusion principal so 1 state can have two electrons with different spin (i.e if one spins up then second spins down) isn't it?

I'm going through the solution to a problem that was assigned to my class and there's a step I don't really understand which I think is a concept I'm misunderstanding. 1. Homework Statement The curved surface of a cylinder of radius R and length L is insulated. The face at x = L is maintained...

Homework Statement My textbook says that the state of plane stress at a point is uniquely represented by two normal stress components and one shear stress component acting on an element that has a specific orientation at the point. Also, the complementary property of shear says that all four...

Homework Statement We mix 1 kg of ice at -10 C with 5 kg of vapor at 110 C. Calculate the temperature of equilibrium. m_i = 1 kg T_i = -10 C m_v = 5 kg T_v = 110 C L_melting = 330 000 J/kg L_condesation = 2 260 000 J/kg c_water = 4200 J/kgHomework Equations Q_given = Q_got Q = L*m = c*m*dT...

Hi PF there is one thing that i cannot understand here. Please look at eqn 1068 I try to compute the first term (without ##V^\dagger##) I get something like ##c_f (t) =-i/\hbar exp [i(\omega + \omega_{fi})t/2] \frac{sin(\omega + \omega_{fi})t/2}{(\omega + \omega_{fi})/2} \}## Unlike eqn 1071...

I would appreciate very much if you could help me with a puzzling question that seems a paradox to me. Every excited state of an atom (every line of the characteristic spectrum) has a “width”: the higher the width, the shorter the lifetime of the state, and when the atom de-excitates we get...

In quantum systems, do you always need to prepare the state (and what does this mean) to make it valid quantum system? But the electrons in the atoms.. no one needs to prepare the state yet they exist as atoms and molecules...

Hi there, I am new to electron theory, and have a question regarding fermi energy. The book I am reading plots the Fermi energy distribuiton function vs Energy for T=0 ( upper right graph in pcture) and for T not equal to zero. The book says that, when T does not equal zero, the decrease in the...

hello, i am looking for a book named "solid state physics: problems and solution" by mihaly and martin. 2nd edition. can anyone please help

Notation: ##J^p## - ##J## the total angular momentum, ##p## the parity = ##+## or ## -. ## Ok so I'm given a diagram of energy levels, all have a ground state of ##0+##, except one which has a ground state of ##1+##. I'm askeed to indentify which set of energy levels belong to which nucleus...

In Griffith books of introduction to QM, it say that Quantum State, mathematically represented as a vector. My problem is with understanding what are the components of such a vector. Do I understand it correctly, that, say, in case of a particle in a box, Quantum State, as a vector is a...

So I've just recently started learning path integral methods in QFT and string theory, and I've heard from numerous sources that the path integral (specifically fermionic path integrals, perhaps?) are objects which are not at all on solid mathematical ground. The feeling I get is that perhaps...

Hi Physics Forums! The ground state electron is the largest negative value, but what does this mean? Does this mean that kinetic energy is a positive value above zero? It seems at the ground state, the electron might also have kinetic energy as it is moving around as well as potential...

Homework Statement https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-xpf1/v/t1.0-9/10980752_10204928958360361_5256945004598578166_n.jpg?oh=7fd9defb14be9a9befa0cf5032def429&oe=55576A2C&__gda__=1431534931_425423ae11039486a001b049726e1b11 Homework Equations Charles Kittel's book on Solid State...

I'm having trouble figuring out how to derive a Hamiltonian for a three state system. I know how to for two state system but for a three state I don't know what vectors I could use to derive the operator. Could someone explain how to do it and give a link to somewhere I read about it

Hey guys, I'm very new to quantum mechanics and have purchased 'Quantum Mechanics: The Theoretical Minimum. I'm still a bit confused by a fairly fundamental idea. In the book, it states that you first prepare a spin state (say the σz = +1) in the initial measurement. If you rotate the...

Our hard drives are reaching the limit of memory capacity and they are studying about the idea of using the molecules and atoms to store memories. Can information or memories be stored in the quantum state? When we heard of quantum state applications in computer, we mostly think about quantum...

QM students study the singlet state, (|u>-|d>)/SQRT(2). Particles in the singlet state can be separated by any distance, and remain in the singlet state. That leads to the EPR paradox, Bell's Theorem and the more. My question has more to do with entering the singlet state. Leonard Susskind...

Homework Statement Consider a particle with mass m in the following 1D potential: V(x)=\left\{ \begin{array}{lr} mgx \ \ \ x>0 \\ \infty \ \ \ \ \ \ \ x\leq 0 \end{array} \right. What is its minimum energy calculated using the uncertainty relation? Homework Equations \Delta x \Delta p...

Homework Statement It's just that in my textbook, for section titled "Second virial coefficients can be used to determine intermolecular potentials," I have an equation that I do NOT understand how it was derived---I tried to do it over and over, but couldn't quite figure how. If anyone could...

Hello All, I am pretty sure that when a nucleus decays via e.c. and goes to the ground state all of the excess energy is released with the emission of the neutrino but was wondering if anyone could confirm/give a reference for this. Thanks!

New York Assembly speaker charged with five criminal counts in corruption case http://news.yahoo.com/york-assembly-speaker-charged-five-criminal-counts-corruption-145959633--sector.html Of course, NY State is equal opportunity in these matters. Joe Bruno, was the Temporary President of the...

Can anyone please recommend sources for questions and problems with soultions related to Solid State Physics I course. For all range of topics from crystal structures up to semiconductors introduction (by Kittel). Thank you.

Suppose one scientist performs a series of experiments, and another scientist does the same thing. But unbeknown to either of them, a highly evolved alien measures all of the particles the first scientist is going to test, just before he does his measurements. Question: Would the two...

Homework Statement In the circuit shown the 120V, 60Hz source supplies the ideal load shown through an ideal 2:1 transformer. What steady state current would you expect to read on the rms ammeter shown (please find the picture attached)? Homework Equations Zeq = (1/Z1+ 1/Z2)^-1 Z1 =...

Dear all, periodic DFT codes (e.g. VASP) effectively simulate an infinite crystal due to the periodic boundary conditions. However, the energy value that one obtaines at the end of a simulation if finite. Frankly, I'm quite confused right now. Is the energy to be understood 'per unit cell'...

Homework Statement For a stretched rubber band, it is observed experimentally that the tension f is proportional to the temperature T if the length L is held constant. Show that: a) The internal energy U is a function of temperature only b) Adiabatic stretching of the band results in an...

Hi. I plan on being an exchange student at Berkeley next year. I cannot find any course description for this course, I only find the description for 141A+141B: http://general-catalog.berkeley.edu/catalog/gcc_list_crse_req?p_dept_name=Physics&p_dept_cd=PHYSICS 141A. Solid State Physics. (4)...

Homework Statement 8.02 × 10−1 moles of nitrogen gas ( γ= 1.40) is contained in a volume of 2.00 × 10−2 m3 at a pressure of 1.00 × 105 Pa and temperature of 300 K. The sample is adiabatically compressed to half its original volume. IT behaves as an ideal gas. (i) What is the change in...

Hi All, I'm in the beginning stages of writing a quantum computer emulator, primarily to get all the concepts down. I've got an excellent Bloch sphere with a Bloch vector that I can duplicate as many times as I like. However, I'm now tackling entangled states. I'm struggling with identifying...

Homework Statement (a)Find energy of photon emitted (b)Show that relative velocities after de-excitation are reversed (c)Find an expression for CM frame energy and find momentum of either particle in CM frame (d)Consider now, for a nuclear process and describe the initial and final conditions...

"Let’s begin by labeling the possible spin states along the three coordinate axes. If A is oriented along the z axis, the two possible states that can be prepared correspond to σz= ±1. Let’s call them up and down and denote them by ket-vectors |u> and |d> . Thus, when the apparatus is oriented...

can anyone suggest any good reading material on operator state mapping in conformal field theory? I know only elementary field theory... So it might be helpful ifsomeone suggest a book where it is done in little detailed way..

I would like to know what is the difference between a solid state physicist and a materials engineer. I mean, do they end up doing the same kind of job or research? If they both have the same purpose, how can they do it having different backgrounds? Which preparation is better for the purpose?

1 what are the various methods/ways, besides quantum entanglement, to put, some of, the photon properties an indeterminate state? 2 what are the various methods/ways, besides polarizers or measurement, to put the photon properties a determinate state?

Mario Cuomo died of heart failure at his home surrounded by family members. http://news.yahoo.com/mario-cuomo--former-new-york-governor--dies-at-age-of-82--reports-010630131.html My condolences to his family, friends and colleagues.