Quantum states Definition and 86 Threads

Hi, Just a little thing that's been puzzling me: Consider a state \mid \psi \rangle = \frac{1}{\sqrt{2}} \mid A \rangle + \frac{1}{\sqrt{2}} \mid B \rangle This is normalised since [\frac{1}{\sqrt{2}}]^2 + [\frac{1}{\sqrt{2}}]^2 = 1 Now let A = B: \mid \psi \rangle =...

I am aware and well read on the decoherence approach to understanding how conglomerations of micro quantum systems will tend to lose quantum coherence via interaction with the environment. The cross terms in the density matrix for the system will tend to zero (due to the partial trace...

I was reading this article, http://www.nature.com/news/2009/090122/full/news.2009.50.html, and it was talking about how they 'teleported' a Ytterbium ion (Yb+) and mid-way through the article it said that they had to destroy the quantum state of the original Ytterbium ion and they did that by...

In measuring the x component of angular momentum of a state, by using the expectation value calculation of Lx, i got i/3 h bar - i/3 h bar, does this means that the probability of h bar is i/3 and the probability of 0 h bar is 0 and the probability of -h bar is i/3? If so, when is the...

Homework Statement how many possible quantum states for a nitrogen atom with electronic configuration of 1s22s22p3 Homework Equations ? The Attempt at a Solution So, the answer for this question is 20, but I can't for the life of me find out how. The book we're given is...

Can anyone help me find out how to work out how many different quantum states are there in the Hydrogen atom with principal quantum number n = 6 and orbital quantum number l = 1? Any help?

Hey everyone, so I recently watched a vid that talked about Googol and googolplex sized universes, and their implications quantum mechanically. Supposedly, the number of quantum states that the particles that make up our body can make is something like 10^10^70. The physicist then said...

How to calculate number of quantumstaes or unit cells within energy range E and E+dE in the phase space to prove the eqn: g(E)dE=[(8π√2V)/h^3]*m^(3/2)√EdE

this wikipedia article http://en.wikipedia.org/wiki/Qubit says i am kind of comfortable with the physics of it, but i am totally lost on the thing about vector space over the complex numbers can someone please lend me a hand? it seems that the more i try to read about it, the less i know

Homework Statement In lecture for stats and thermal, we briefly talked about quantum states and went through an example. However, the lecturer simply told us the answer to the second part of the question without going through it. Here's the question: 1a.) How many molecules of H2O are in...

http://www.sciencedaily.com/releases/2011/03/110331104014.htm ScienceDaily (Mar. 31, 2011) — Do the principles of quantum mechanics apply to biological systems? Until now, says Prof. Ron Naaman of the Institute's Chemical Physics Department (Faculty of Chemistry), both biologists and physicists...

Title may sound weird,but I think it might be worth exploring In axiomatic formulation of quantum mechanics, quantum states are postulated as vectors residing in Hilbert space. The only apriori requirement that Iam aware of ,for a quantity to qualify as a quantum state, is that it should...

I happen to be studying the basics of quantum mechanics at the moment and have made acquaintance with the vector representation of quantum states, in particular the two states of electron spin. For this question let's just say the spin can be up or down. The state of the spin is...

can somebody simply explain what is meant by NEGATIVE QUANTUM STATES , as given by dirac in his theory?i know its not as SIMPLE as i want it to be , but still I would like to know its significance in the most basic way!

I am doing some research on Bose-Einstein condensates and was hoping someone could give me a non-mathematical reason as to why bosons 'want' to occupy the same ground state. I think its details come from Bose-statistics, but is there a simplified way of explaining it? Thanks

Hello, I am trying to express a given wavefunction through different basis, momentum and position. Look at 5.2(b) and (c) through the link: http://qis.ucalgary.ca/quantech/443/2011/homework_five.pdf" I complete part (b) by doing the following...

As I understand it, the Pauli exclusion principle states that no two like fermions can be in identical quantum states. I also understand that the quantum states are thus: n, which is the electron shell, l, which is the subshell, m_{l}, which is orbital, and m_{s}, which is spin. However, it...

Towards the end of http://www.youtube.com/watch?v=IAgV-LKTiMI&feature=channel" video at 54:55, the professor defines the four possible states of two entagled electrons as follows: singlet |0,0> = |u,d> - |d,u> triplet |1,1> = |u,u> |1,0> = |u,d> +...

I was just wondering because it seems there is a contradiction in qm. If a quantum state can only be represented by an abstract statistic then would not gravity be equally subjective until decoherence occurs? And what about entanglement? It appears to act as a constant (an immediate one)...

Homework Statement The components of the initial state |\psi_i> of a quantum system are given in a complete and orthonormal basis of three states |\phi_1>, |\phi_2>, |\phi_3> by <\phi_1|\psi_i>=\frac{i}{\sqrt{3}} <\phi_2|\psi_i>=\sqrt{\frac{2}{3}} <\phi_3|\psi_i>=0 Calculate the probability...

Consider a particle in an infinite square well described initially by a wave that is superposition of the ground state and the first excited states of the well: Ψ(x,t = 0) = C[ψ1(x) +ψ 2 (x)] (a) show that the value C =1/ 2 normalizes this wave, assuming 1 ψ and 2 ψ are themselves normalized...

i'm given either |0> or cos\phi|0> + sin\phi|1> by a fair coin toss. and I don't know which state I'm given. i need guess which state was chosen. i think the method is to do a unitary operation on the states, and do the measurement, but I'm not sure how to construct a unitary, and I'm still...

Sorry for a (maybe) dumb question, but... I understand that according to QM, the description of the situation for a particle or system is described by a linear superposition of the wave functions of all the possible states (eigenstates) of the system. When a measurement is made, the wave...

Hey, I've been looking into different aspects of distinguishing two pure quantum states. I've ended up reading a lot of books/papers covering things like "accessible information", but there haven't been too many explanations on how to find optimal measurements. The book by (Kaye, Laflamme...

normalising \psi=|1,-1> is easy as \psi^*=<1,-1| and then \psi^* \psi = <1,-1|1,-1>=2 which gives \psi= \frac{1}{\sqrt{2}} |1,-1> for the normalised ket. but what about \psi=|1,-1>+2|0,0>+|-1,1> i get \psi^*=<1,-1| +2<0,0| + <-1,1| now I am guessing that seeing as i want to normalise...

Hi could someone please explain the what the bloch sphere representation of a quantum state is useful for? thanks Mark

Hello, What is a quantum state? Put generalised functions/Schwartz distributions to one side, because a) they're not a Hilbert space, and b) they can't be multiplied, so it's hopeless to even begin to think about Feynman diagrams. One-particle quantum states seem to be fairly well...

Two Einstein solids are joined so that they can exchange energy. One contains N_A oscillators, the other N_B oscillators. Apparently, the possible number of quantum states of the combined system is given by, g(n,N) = \sum_{n_A = 0}^n g(N_A,n_A)g(N_B,n-n_A) where n is the principal quantum...

Hydrino and "Inverse Quantum States" Stumbled upon this recently. http://en.wikipedia.org/wiki/Hydrino Is there a general consensus about this? I found reference three (3) to make some interesting arguments, but I'm certainly not qualified to critique this.

Suppose you had a divide which, upon input of one of two non-orthogonal quantum states \left|\psi\right> or \left|\phi\right> correctly identified the state. How could you use this device to clone these states (in violation of the no-cloning theorem)?

Homework Statement The quantum state of a particle can be specified by giving a complete set of quantum numbers (n, l, m_s, m_l) . How many different quantum states are possible if the principal quantum number is n = 2? To find the total number of allowed states, first write down the...

Is it generally true that the ground state of a given quantum system corresponds to the lowest quantum numbers? If so, how do we know this?

Assume there are two particles which share the same quantum states (that is, if I understand correctly, both are probabilistically identical), but have not been through the process of entanglement. Let's assume they never interacted in any dimensions, they just happened to be identical. Would...

The Kodama state has been the "If-Only" of post-string Quantum Gravity for several years, since Smolin's 2003 paper "Quantum Gravity with a Positive Cosmological Constant" if not before. As in----if only the Kodama state was normalizable, if only we had the Kodama state then we would have a...

how to create "good" quantum states from "good" quantum numbers? I think I am finally understanding what the "good" quantum numbers are in degenerate perturbation theroy. Basically, given a perturbation H', if [H', L^2] = [H', S^2] = [H', J^2] = [H', Jz] = 0, then l, s, j, and mj are the...

what are the 32 quantum states of an electron?