Superposition Definition and 673 Threads

By 'Genuine Decoherence' - I mean collapse of the wave function by a theory and its mathematical equations. If a micro system encounters a macroscopic apparatus - in collapse theories a definite state appears for both the apparatus and system, but after a tiny time since the system entangled...

Two waves are perfectly superposed (traveling same direction), but are 90 degrees out of phase. Does this result in destructive or constructive interference, as the waves could be seen as either half anti-phase or half in-phase. For example, the first wave has an amplitude of 1. The second wave...

Quant.Entaglement:Difference between superposition of spins and not knowing the spin? [SIZE="3"]Let two electrons' (A and B) spin be entangled. They'll be in a superposition of up and down spin. When the spin of A is measured it settles randomly to up and instantly B is set to down. What...

[SOLVED] Superposition of two wavefunctions Homework Statement The problem is more of complex number arithmetic more then conceptual : Homework Equations |\psi|^{2}=\psi\psi^{*} The Attempt at a Solution I simply used the equation given above, but instead of getting 2Re{...} I...

Homework Statement A particle in an infinite square well has as its initial wavefunction ψ(x,t=0) = (1/√2)[φ1 + φ3]. Find |ψ(x,t)|2. Express it as a sinusoidal function of time using ω= π2*h/(2mL2). Homework Equations Note that φn = √(2/L)*sin(nπx/L) for a well of width L. The...

This is an extract from my third year 'Foundations of QM' lecture notes: If ψ1 and ψ2 are admissible states, then the superposed state \alphaψ1 + ψ2\beta ( \alpha,\beta \in C ) is also an admissible state. \rightarrow complex vector space. I understand that a linear superposition...

Homework Statement The wavefunction for a particle in one dimension is given by ψ1. Another state the particle may be in is ψ2. A third state the particle could be in is ψ3. Looking at the wavefunctions, ψ3 is ψ1 and ψ2 added together. Is the probability of being in a given interval in...

Hi there. A quick question: When calculating the average energy (or any value) of a particle which is in superposition, why the sums have different summation index (n,m)? Thanks!

In a linear superposition, what is the relationship between expectation value of, say, energy and the amplitude coefficients of the eigenfunctions?

Homework Statement Consider two normalised, orthogonal solutions of the TDSE (Note all my h's here are meant to be h-bar, I'm not sure how to get a bar through them). \Psi_1 = \psi_1 (x) e^{-E_1 it/h} \Psi_2 = \psi_2 (x) e^{-E_2 it/h} Consider the wavefunction \Phi =...

I was reading about how scientists have been able to perform experiments and successfully managed to get a beryllium atom into a superposed state whereby the atom had a 50/50 change of having its spin as either up or down. But how can they tell that its in a superposition as surely the act...

Homework Statement Demonstrate the relation between the expectation value and the measurement outcomes of an observable of a particle by conisdering as an observable the kinetic energy operator E=p^/2m when the particle is in a superposition of 2 momentum eigenstates Homework Equations...

What of importance of superposition in quantum computing? What I understood is we have two states |0> and |1> which represent logical 0 and 1 . So the mixed state can be given by the combination of logical operators like OR, AND and NOR Etc. For example 1/3 |0>+2/3 |1> The particle...

I understand that an object can exist in many possible locations, and that when you're not looking, it is a wave. It's only when you look that it manifests itself into a particle. But Is that also dependent on the measurement of sound? Does an object materialize when you hear it, or feel a force...

I know how to add harmonic oscillations on the same axis but i was wondering why can i do it? If i have x1(t)=Asin(w1t +fi1) and x2(t)=Bsin(w2t +fi2), why can i say that the resultant motion is x=x1+x2. Once again I am not interested in the solution because i know how to derive it but how to...

Homework Statement I need help with determining the current through the 1Ω resistor. http://img403.imageshack.us/img403/5422/acex22.jpg The trouble I have is that the voltage sources are phased as given in picture, and I got stuck on how to deal with these phases when calculating the...

Almost every EE I've talked to claims that you need to leave dependent sources in when using superposition to solve a circuit. I had a professor in undergrad who used to claim that statement is invalid. I've used his method since I learned it without any concern. I never saw any problem with...

I understand the basics of the mathematical descriptions of systems in superposition. But what I'm not clear about is whether such a system is actually in more than one state at the same time. Is this a matter of QM interpretation or is it simply moot b/c we can make no measurements that can...

Hello, I have no idea how to do this problem! I have solved all my homework problems except this one can someone please help! Suppose a singer singing F# (370 , the fundamental frequency) has one overtone of frequency 740 with half the amplitude of the fundamental and another overtone of...

hi everyone, i was wondering whether i can change this sentence ( if the phase difference changes rapidly , the average effect of no interference is recorded.) to( if the phase difference changes rapidly , the average effect of no superposition is recorded.) as i remember that the term...

Hello! If we want to find i3, we can apply the superposition theorem to the circuit below. It gives For V2 set to 0: i3' = V1 / R1 For V1 set to 0: i3'' = V2 / (R1 || R2) i3 = i3' - i3'' = V1/R1 - V2 / (R1 || R2) i3 = 10 / 500 - 2.5 / 83.3 = -0.01A My question is Do the i3' and i3''...

I know this problem is simple enough but I can't get the hang of it Find the electric field at point A in the diagram if (a) q1=2.00 μC and q2=3.00 μC. (b) q1=2.00 μC and q2= -3.00 μC. Thank you. P.S. If you can explain how you solved the problem that would be great. I'd really like to know...

Greetings, I have a question on superposition of two waves and I am pretty new to the topic. I am not contended with my solution and seek your evaluation. Any suggestion, comment is welcome. Thanks in advance. Homework Statement Consider the superposition of two waves x1 = A1...

I've watched the Susskind lectures on QM and Quantum Entanglements. Susskind seems to avoid many of the interpretation issues inherent in QM. For example, he never talks about the wave function collapsing due to the involvement of "conscious mind". He does show, mathematically, that wave...

Homework Statement Determine the amplitude and phase of the luminous disturbance produced by the superposition of N waves of the same amplitude and phases which increase in an arithmetic progression (\delta,2\delta, ...n\delta) The Attempt at a Solution Using the trig identity...

So my physics textbook briefly mentions What I don't understand is: If the paper is put between the charges, those charges would induce a dipole, right? Since there are charges on both sides and "like-charged" which way would the dipole point. The book says the tape is attracted to the paper...

Edit: This is my first post. This question isn't related to any homework problems but was inspired by my physics book. I apologize if this is the wrong forum but It seemed the right place based on the other posts. So my physics textbook briefly mentions What I don't understand is: If the...

As the story goes Schrödinger's cat was in a quantum box with a radiation source, if the device detected a radiation leak it would trigger a device to break a vial of poison, killing the cat. The point of the story is a thought experiment as to if the cat is alive or dead before observation...

Homework Statement Use the superposition method to find the magnitude and direction of the current flowing through the 10 ohm resistor. Then use any technique other than that used previously to check the validity of your answer Homework Equations The Attempt at a Solution First...

Suppose a given second order linear differential equation has two different solutions; then it follows that their linear combination is also a solution. If y_1(x), y_2(x) are two solutions then y(x)=a_1y_1(x)+a_2y_2(x) is also a solution where a_1, a_2 are two constants. If we consider the...

In the problem attached do you use superposition theorem. if so how do you use it? I don't know how to solve circuits with 2 voltages.

I was recently watching a video about the double slit experiment that said if we fire electrons one by one, the QM superposition principle says that the single electron goes through both holes, goes through one, vice versa, and none all at the same time. i.e a Superposition of states. However...

Hello, :smile: I was doing a superposition problem and got stuck on this point: http://img810.imageshack.us/img810/1866/superti.jpg Please help me out. Thanks Cheers

Homework Statement Charge q1 = 1.8 10-8 C is placed at the origin. Charges q2 = -1.7 10-8 C and q3 = 2.6 10-8 C are placed at points (0.18 m, 0 m) and (0 m, 0.24 m), respectively, as shown in the figure. Determine the net electrostatic force (magnitude and direction) on charge q3...

Is a living macro object, such as a cat or human being, in fact in a superposition of states? (I am thinking about for instance the multiple-universe idea)

I am confused by an aspect of the infamous double slit experiment. It is said that one way to understand why a succession of single particles can give rise to an interference pattern is that a single particle could be going through both slits simultaneously and interfering with itself. But this...

Homework Statement If sound waves superimpose, why is a person in the audience able to distinguish different sources of sound eg flute and guitar. Homework Equations Amplitude (A+B) = Amplitude (A) + Amplitude (B) The Attempt at a Solution No idea

Hi, is it true that only Observables can be in Superposition? Meaning superposition of dead and live cats is invalid by some unknown mathematical reasoning? Jambaugh stated thus in the other forum that only observables can be in superposition. What's the mathematical or quantum logical proof...

Is it possible to put a Boson and Fermion in superposition? If not possible, why not?

1. PROBLEM Q: write down an expression for a superposition wavefunction \Psi(x) for an electron in a 1D box of length L consisting of the n = 1, 2, and 3 states. show that C12 + C22 + C32 = 1, and Cn represents the coefficients of the n state. 2. RELEVANT EQUATIONS see word document...

Homework Statement Two pulses with the same amplitude are moving toward each other on a rope as shown. Which of the following statements describes their behavior? (A) They will reflect off of each other and reverse their directions. (B) They will cancel out, leaving no pulses in...

Given that E(n) = (n^2)E, and that our wave function PSI = 1/Sqrt(14)(Psi(1) + 2*Psi(2) + 3*Psi(3), what is the the value for the measurement of the energy? So, <H> = SUM((c(n)^2)*E(n)) where E(n) = (n^2)*E and c(1)=1/sqrt(14), c(2)=2/sqrt(14), c(3)=3/sqrt(14), which satisfies...

Homework Statement Two pulses of the form e^-(x + 4)^2 e^-(x - 2)^2 travel in opposite directions along a tensed non dispersive rope. If the speed of propagation of both pulses is 2 cm/s, find the instant of time in which the wave's amplitude goes to zero, if it exists. Homework...

Would an accurate analogy for superposition (e.g. Schrödinger's cat) be like tossing a coin? While it's in the air it could be heads or tails, no way to know for certain. But, as soon as it lands, one outcome emerges.

Anyone familiar with both quantum mechanics and cosmology here. Say. How much dynamics can occur in the deterministic Schroedinger Equation in its evolution while it is in unitary state (before collapse)? For example. Is it possible for the Big Bang and evolution of stars to solar system and...

How much dynamics can occur in the deterministic Schroedinger Equation in its evolution while it is in unitary state (before collapse)? For example. Is it possible for the Big Bang and evolution of stars to solar system and planets to occur while everything is inside a superposition (that...

Homework Statement I have to find I3, I've already easily found the first component I3| but i don't understand how i can get I3||. I thought about a Wheatstone bridge but doesn't work looking at the data. The result is I3=-7 A

Hi I am currently reading John Preskill's Lecture Notes on Quantum Information and Quantum Computation (see http://www.theory.caltech.edu/people/preskill/ph229/index.html near the bottom of the page). I am confused about what he writes in chapter 2.5.4: Quantum erasure. He starts with the...