State Definition and 1000 Threads

I have to find a unitary transformation that takes me from one quantum state to another (or if there is such a transformation), given the two quantum states in matrix form. The matrices are huge (smallest is 16x16) , so doing it on paper is not an option. Does anyone know how I can do this in...

Homework Statement Find a state vector |v> ∈ ℂ^2 such that if a measurement of δx is made on a qubit in this state, then the prob. of obtaining the value of +1 in the measurement is 9/10. What is <δx> in this case? Homework Equations State Vectors: https://en.wikipedia.org/wiki/Quantum_state...

Hello all, quick question: When Plasma cools what state does it return to? Is it a liquid or the state it was in before at room temperature? Do the atoms rearrange into what it was like before i.e. the same element or something completely different? Thank you

Homework Statement Calculate the average potential and kinetic energies for the electron in the ground state of hydrogen. Homework EquationsThe Attempt at a Solution I know that KE = E - <U(r)>. I know that E = (-KZ^2e^2)/(2a0) and I know that U(r) = -KZe^2/r but I can't figure out how to...

Homework Statement In a jet engine, a flow of air at 1000 K, 200 kPa, and 40 m/s enters a nozzle, where the air exits at 500 m/s and 90 kPa. What is the exit temperature, inlet area, and exit area, assuming no heat loss? Homework Equations min = mout = m where m = mass air flow dE/dt cv = Qcv...

I understand the basics of neutrino oscillation from the starting point of each neutrino flavour state being a superposition of mass states, or vice versa. However, the introductory texts I've seen never seem to explain what motivated such an idea. What made Pontecorvo think this?

Problems stated in attached pictures.So could someone explain me what am I doing wrong here this is solution for the example a) . I tried it twice and I am getting wrong results. Thanks in advance.

Hi, I am proficient in standard dynamic programming techniques. In the standard textbook reference, the state variable and the control variable are separate entities. However, I have seen examples in economics, in which a single variable, let's say consumption, is both a state variable and a...

Homework Statement An ideal AC voltage source generating an emf V (t) = V0 cosωt is connected in series with a resistance R, an inductance L, and a capacitance C. a) Find the steady-state solution for the charge, q(ω,t), which is of the form q0(ω)cos(ωt− δ(ω)). b) Find the steady-state...

Homework Statement A system in thermal equilibrium at temperature T consists of a large number of subsystems, each of which can exist only in two states of energy and , where . In the expressions that follow, k is the Boltzmann constant. For a system at temperature T, the average number of...

Using the single-electron wave function ψ(r) = N*exp( −ζr2 ) with ζ a variational parameter, how can we calculate the best approximation for the ground state energy of the hydrogen atom?

The more detail you can see the attachment. I don't understand why Rabi translate the state along z axial to H axial as shown the equations (8).

Molecules do not use magnetic energy as latent heat - adding magnetic energy does not cause a phase change. If electrical conduction indeed required energy state changes, then during electrical conduction, a change of energy state would likely consume magnetic energy as latent heat, instead of...

How to understand that Bloch wave solutions can be completely characterized by their behaviour in a single Brillouin zone? Given Bloch wave: \begin{equation*} \psi_{\mathbf{k}}(\mathbf{r}) = u_{\mathbf{k}}(\mathbf{r}) \exp (i\mathbf{k}\mathbf{r}) \end{equation*} I can write wavefunction for...

Homework Statement The oxidation state of oxygen in all compounds is -2, except in peroxides such as H2O2, Na2O2 and BaO2 where it is -1. If it is -1, then why can't we write H2O2 and Na2O2 as HO and NaO respectively?

A check my work question... Homework Statement Louis de Broglie tried to explain Bohr’s hydrogen atom electron orbits as being circles of just the right circumference such that an electron of the Bohr energy going around the circle will interfere constructively with itself. This seems to...

I was wondering , are there any materials , metal or others, that have ions as the charge carriers that form current instead of electrons as in most metals.? and are the ohmic resistance in room temperature for example similar to materials were current is formed by electrons or is the resistance...

Hi everyone, I am a fourth year undergrad in physics. I am strongly considering graduate study in materials science, and I am wondering which course might have more impact both on my future studies and on admissions. The materials course seems like a broad overview of the subject, going over...

I am trying to undersand Ashcroft's derivation of energy density on page 38. I am following most of the arguments save EQ 2.30. Where did the vector go? I did follow my professors argument for converting to polar/spherical when the argument of a function is a modulus of a vector — exploiting...

What is the best book in solid state physics that contains problems and solutions?

Hello, I have a fundamental question about why state space control techniques are superior to the classical methods. I l know that you can control a system with multiple inputs and outputs for several states using state space control, however, can't the same thing be done in classical control...

Homework Statement [/B] Consider a hydrogen atom which, in t = 0, is in the state given by \psi(\mathbf{r},t>0)=\frac{A}{4\pi}R_{10}(r)+\frac{cos\alpha}{4\pi}\left(\frac{z-\sqrt{2}x}{r}\right)R_{21}(r) Expand ψ in terms of the {Φnlm} basis of normalized eigenfunctions...

Homework Statement Case, P[bar], T[C], v[m3/kg], u[kJ/kg], x[quality], State a) 1.5, ?, ?, 3000, ?, ? b) ?, 120, .6, ?, ?, ? c) 3, ?, ?, 2543.6, ?, ? d) ?, 190, ?, ?, 20%, ? e) 25, 100, ?, ?, ?, ? f) ?, 240, ?, ?, 0, ? Homework Equations We are supposed to use the steam tables in the back of...

In Ballentine's Quantum Mechanics book, as part of a discussion of pure states vs non-pure (mixed) states, he says Polarized monochromatic light produced by a laser can approximate a pure state of the electromagnetic field. Unpolarized monochromatic radiation and black body radiation are...

Homework Statement A tank has a saturated liquid at 0.2 MPa. An amount of heat is transferred until the pressure in the tank became 0.1 MPa. If the volume of the tank 1 m3. Determine: 1- The final state of the water 2- The mass of the vapor in the tank 3- The work 4- The process on P-v...

Hello I've been wondering how certain solid state lasers could have a continuous lasing action (Nd YAG laser for instance ) If so,the understanding that the best lasing conditions are when the temperature Is lowest gets disproved(considering that a commendable quantity of heat is produced during...

Hi all! As a republican (libertarian to be exact) I would only consider voting for 10 out of the 17 candidates (I mean, if I were voting age). The 7 I would never vote for are in that place because of their lack of understanding of the separation of church and state. I just don't understand how...

The state, ##| S\rangle##, say, of a system is represented as a vector in a Hilbert space. ##\psi (x, t)## is the representation of the state vector in the position eigenbasis; ##\psi (p, t)## in the momentum eigenbasis et cetera. That is, ##\psi (x, t) = \langle x|S\rangle##; ##\psi (p, t) =...

Does an exchange of two identifical particles (electrons) lead to a new microscopic state?

Entropy of any system is state dependent. I just read about thermodynamics and I got this question. I first set my system which contained my classroom, the hallway connecting my physics teacher's cabin and the classroom. Then let the entropy of the system be S when I was going to the classroom...

So another thread here got me thinking about piezoelectronics. From what I saw there and from what I can find, people have only been able to produce voltages capable of charging 1.2V batteries. Are there any that are capable of charging 3.7V batteries or has our technology not progressed that far?

I started to study statistical physics from a book, and it starts with basics about statistics and probabilities (which are things mostly new for me). In the book there is the following statement: "The simplest non-trivial system which we can investigate using probability theory is one for...

Hi all, I'm trying to understand how to calculate the time dependent expectation value of the atomic dipole moment for a superposition state, and I have a good guess to check with you. Say we have \psi = \frac{1}{\sqrt{2}} \left[ \psi _{100} + \psi _{310} \right] at t = 0. Then, for t > 0: \Psi...

I have been reading about Z2 topological invariant recently. However, after some literature survey, I still cannot understand Z2 invariant in language of time reversal polarization. Basically, my struggle includes the following two questions: As the ref paper says(see the picture below): On...

Hi, I am trying to find the wavefunction of a coherent state of the harmonic oscillator ( potential mw2x2/2 ) with eigenvalue of the lowering operator: b. I know you can do this is many ways, but I cannot figure out why this particular method does not work. It can be shown (and you can find...

Can you please explain the difference between ground state and stationary state? In the stationary state, are the electrons at rest inside the atom?

Homework Statement max. Turbine work output rate: 6.0MW Turbine isentropic efficiency: 90% Turbine exit state (isentropic): 40KPa, x=92% Turbine and pump actual process are assumed adiabatic Find turbine inlet state: Pinlet, Tinlet, Sinlet Homework Equations W = ΔH h = hf + xhfg The Attempt...

I've been trying to figure out how to calculate if a satellite is in view of a ground station (and above a certain elevation) using just position vectors for both satellite and ground station. Does anyone know of an equation, algorithm, etc. that does this? Thanks

do each point in solid have a special energy state?

Homework Statement (f) At t = 0, a particle of mass m trapped in an infinite square well of width L is in a superposition of the first excited state and the fifth excited state, ψs(x, 0) = A (3φ1(x) − 2iφ5(x)) , where the φn(x) are correctly-normalized energy eigenstates with energies En. Which...

A book said that the PE of molecules increase during melting of ice but shouldn't it be decrease since the distance between molecules increase ?Isnt the force between the molecules determine the PE?

[Moderator's Note: Changed level of thread to "Advanced" based on the topics being asked about, all are graduate level topics.] I feel that I have an inadequate understanding of many important concepts in condensed matter physics, so I want to try to learn at least the most basic parts. So what...

This is one of those question you won't find the answer in any book. From Wikipedia: it is impossible for two electrons of a poly-electron atom to have the same values of the four quantum numbers (n, ℓ, mℓ and ms). But how can an electron know the state (the quantum numbers) of the other...

Hello,I'm new here and this is my first post. I am a freshman electronics and communication engineering student.I didn't study any quantum mechanics or solid state physics before(not in high school). But for my first year course i need to study solid state physics.The books we are suggested to...

What do you know and think about the state of power in general in the United States (for example the coal industry)? What do you know and think about the state of nuclear power in the United States? Do you think there should be more or less support for it and why? How dangerous is a nuclear...

Hi everybody! Why we don't have to prove Lorentz invariance of the Vacuum state in QFT? This fact is quite obvious in QED and follows from Lorentz invariance of electric charges. But in general case? I don't know, but it seems to me this fact is not so obvious as it treated.

Mathematically, a state in QM is a ray on the Hilbert space. But: 1) How would you define "state" from a physical point of view? I know a lot of examples but not a general definition. 2) Given a specific quantum system, to find all the states and so the Hilbert space, all I have to do is to...

< Mentor Note -- thread moved to HH from the technical chemistry forum, so no HH Template is shown >[/color] I need someone to check my answers and help me with the questions I couldn't answer. What is the max. # of electrons located in the groud state of a) an orbital 2 b) d sublevel 10 c)...

Hello. I need help with the following: Suppose a basis set of states $\varphi_i$. Calculate the effect of the operator $\widehat{R} \equiv \Pi_i \left( \widehat{Q} -q_i \right)$ on an arbitrary state $\Psi$, assuming that the equation $\widehat{Q} \varphi_i = q_i \varphi_i$ is satisfied. I'm...

Is it simply the gaseous state of a liquid substance? For instance, water vapor, in this context, would be the gas state of water after having transitioned from a liquid state.