State Definition and 1000 Threads

Homework Statement I am given this state, which is the result of a lamba particle decaying into a proton and neutral pion. Initial j = 3/2. The final state can theoretically be written as: I have already determined that: alpha_p = Sqrt[2/3] beta_p = Sqrt[1/3] alpha_d = -/+ Sqrt[2/5]...

Hello, I've been trying to find <p'|φ(x)|p> for a free scalar field. and integral of <p'|φ(x)φ(x)|p> over 3d in doing the space In writing φ(x) as In doing the first, I get the creation and annihilation operators acting on |p> giving |p+1> and |p-1> which are different from the bra state |p>...

Im trying to wrap my head around this. If a photon of the right energy hits an atom's electron (hydrogen e.g) it jumps to the next orbital shell, then goes back down to conserve energy releasing a photon in the process. is this how we see the atoms in everyday matter? by the switching of the...

Hello, In which way nano and solid state physics improve technology? where we use statistical physics more in nano physics or particle physics? where we use quantum mechanics more in nano physics or particle physics? which major is more enjoyable nano or particle physics? which major is more...

I have been doing a literature survey about topological insulators for some time. What surprises me is the close relation between difference of chern number and number of edge states. However, I found most review or tutorial in topological insulator avoided direct proof of the relation. So can...

Homework Statement A satellite is orbiting Earth with a period time of T=110 min. At the ascending node, the state vector of the satellite is rAN =[4500 7100 ?]T km At the northernmost latitude, the state vector of the satellite is rn=[1700 ? 7000]T km. The question marks imply that the...

Homework Statement Imagine a hypothetical process in which the methane molecule, CH4, is "expanded," by simultaneously extending all four C−H bonds to infinity. We then have the process: CH4 (g) → C(g) + 4H(g) Compare the reaction for the "expansion" of methane with the reverse of the reaction...

Homework Statement While studying alkaline Earth metals of the s block elements I found this equation : Be (OH)2+2HCl +2H2O →[Be (OH)4]Cl2 It is clear that in the complex, the oxidation state of Berrylium is +6. But how is even that possible? Homework Equations None The Attempt at a...

All that I've read about black holes describe something so massive it's gravity overcomes all other forces and it causes a region of spacetime to develop that no particle or electromagnetic radiation can escape from. That explanation since it depends on mass makes no sense in regard to...

In section IIIA (p11) Max Tegmark tries to prove that the integrated information Φ of a bell state is zero. The definition of Φ that Tegmark uses is given by the mutual information I minimized over all possible factorizations. The bell state has I=2 when written in the usual basis. Tegmark...

Homework Statement Investigate electronic bands in one-dimensional crystal in weak potential $$V(x)=\sum _n V_0(H(x-na)-H(x-na-a/3))$$ if ##H(x)## is Heaviside Theta function. a) Determine primitive cell, reciprocal mesh and first Brillouin zone. b) Calculate the difference between energy...

Homework Statement A cylindrical tank, with a diameter Db, open to the atmosphere, is drained through an orifice in the bottom of the tank with a diameter Do. The speed of the fluid flowing through the orifice is given by v = \sqrt{2gh}, where h is the height of the liquid measured from the...

Hello. I am completely new to MATLAB and programming in general. I never thought I would have to resort to online help, but here I am. I have spent hours googling and haven't been able to get very far. 1. Homework Statement Calculate the distribution of the temperature of the inner part of the...

Homework Statement [/B] ZnS crystalizes in the B3 type structure with the space group is F¯43m. This structure is shown below and can be regarded as the bi-atomic form of the diamond lattice (F d¯3m). Upon applying a force along the [1,1,1] direction, the crystal might experience a change in...

I have a few questions about entropy and path Scenario I have a closed system of Ideal Gas- Volume is Fixed , Mol Vol is fixed. At room temperature the system is in thermal equilibrium with its surroundings I then cool this system removing Q . To this system I then re-add Q until it is again in...

To my understanding, QED is about electromagnetic interaction, and in a solid system, the interaction is only electromagnetic So why there are stills lots of research in solid state physics ? Is there something not explained by QED ?

Hello everybody, For my thermodynamics test I have to tell whether or not a quantity is a state function, which is obviously not all too difficult when regarding entropy, enthalpy etc. on their own. However there are a lot of questions where it is about "H-S" or "G-H". Are these not always...

Homework Statement a) If a spin-1/2 particle is in the up spin state along z, what is the probability that if its spin along the y-direction is measured it will be found to be pointing in the “up” direction along y? (b) Calculate the expectation values of the components of S, i.e. {Sx, Sy...

Firstly, I apologise for any lack of understanding, incorrect assumptions or misinterpretations of the very little I know about physics, quantum mechanics & quantum computing. I am not an academic, scientist or mathematician, but a software engineer with an interest in quantum computing and...

In 1-D if I have an infinite potential at x<0 so the wavefunction is zero for x<0 but for x>0 the potential is zero so the wavefunction oscillates to infinity is that a bound state ? I presume this isn't bound as it can't be normalized but most definitions state that bound means the wavefunction...

I'm really confused about Energy and Entropy's equations of state, and how their differentials work. So I find everywhere that H = U + PV. And so dH = d(U +PV) = dU + PdV + VdP Ok, that makes sense. But then I look at energy and try to get the equation of state dU = δqrev + δwrev. That also...

A neutral atom of radium isotope may be represented by: 228 Ra (88 proton number, 228 nucleon number). 88...

Homework Statement For the circuit in (Figure 1) , suppose va=10cos16,000tV vb=20cos4000tV. Suppose that R = 700Ω . Write the steady-state expression for io(t) as io=I′ocos(ω′t+ϕ′)+I′′ocos(ω′′t+ϕ′′), where −180∘<ϕ′≤180∘, −180∘<ϕ′′≤180∘, and ω′>ω′′. Find the numerical value of I′o. Find the...

Homework Statement VHDL code: http://i.imgur.com/UZrK1ky.pngHomework Equations B2 = B7 * A1 B3 = (B9 * B2) + (B1(1) * /B1(0) * /A1 B6 = B9 + /A1 B8 = B2 + (B9 * /A1) + (/B5 * (A1 + B7)) If Clock = 1 and rising edge on A2 then we reset B4, B5, B7 to 0. Else B4 = B3 = (B9 * B2) + (B1(1) * /B1(0)...

Homework Statement For a hydrogen-like “atom” (e.g., He+ ion), with nuclear charge Ze, it is claimed that the the ground-state wavefunction is spherically symmetric and is given by ψ(r)=Aexp(−αr) , where A and α are constant. (a) Determine the normalization constant A in terms of α. (b)...

Hello Two temperatures state in non-equilibrium plasma has different vibrational temperature and translational temperature. Vibrational temperature is more than translational temperature usually. Help me to find a book or article for describing thermodynamics of this state.

Homework Statement Determine the state of stress at point A on the cross section at section a−a of the cantilever beam. Take P = 350kN . Homework Equations Um . . . σ = P/A ? The Attempt at a Solution Yeah I'm not quite sure. I thought it was P/A, using 350000N as "P" and 300000mm^2 as A, but...

Hi, thank you for your help in advance. I have a circuit configured as shown in this image. I got this arrangement from an earlier thread. An arduino controls a DC solid state relay, and it works fine when my load is a simple LED. The arduino is controlling through a digital output header and...

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...

Homework Statement A think film of ErAs(rock salt structure, a=0.574nm) is grown on top of a thick GaAs (Zn-blend structure, a=0.565nm) substrate. The substrate orientation and the film growth direction are both <001>. For very thin films, the ErAs is tetragonally distorted such that its...

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...