Quantum Physics Forum

Join in expert discussion on quantum physics. Quantum physics is the mathematical description of the motion and interaction of subatomic particles. Quantum Mechanics and Field Theory.

Threads

Graduate Can there be multiple ground states?

  • marc32123
  • · Replies 1 ·
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Graduate How are atoms not in superposition if the electrons are

  • batmanandjoker
  • · Replies 10 ·
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10

Graduate Commutators, mutual eigenkets, and observables

  • unscientific
  • · Replies 7 ·
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7

Undergrad Less than one photon, what does it mean?

  • suma
  • · Replies 6 ·
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6

Graduate Left hand side of the Schrödinger equation

  • mpv_plate
  • · Replies 16 ·
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16

Graduate Why is a massless spin-2 automatically a graviton

  • Sonderval
  • · Replies 21 ·
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Graduate Transition Rates / Squared Dirac Delta

  • MisterX
  • · Replies 2 ·
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Graduate Recommended Books for Beginners in Particle Physics

  • Moeen
  • · Replies 3 ·
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3

Graduate What state do we have if we don't know if a measurement was performed?

  • greypilgrim
  • · Replies 20 ·
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Graduate Matrix Elements: LHO & Dirac Notation

  • LagrangeEuler
  • · Replies 2 ·
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Graduate Phonons: For oscillator wave function

  • LagrangeEuler
  • · Replies 12 ·
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Graduate Klein Paradox - Dirac equation with step potentional

  • Drew Carey
  • · Replies 1 ·
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Graduate Why do bound systems have less rest mass than the sum of its parts?

  • dimwatt
  • · Replies 5 ·
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Graduate Is the Stern-Gerlach experiment sufficient?

  • intervoxel
  • · Replies 4 ·
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4

Graduate Planck and Maxwell-boltzman distribution

  • Entanglement
  • · Replies 1 ·
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Graduate The Dirac Lagrangian Density: A Brief Overview

  • "Don't panic!"
  • · Replies 17 ·
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17

Graduate Definition of a Gaussian wave packet for a Initial State

  • Gabriel Maia
  • · Replies 5 ·
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5

Graduate Passing a black kole from double slit experiment setup

  • us40
  • · Replies 6 ·
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6

Graduate The one-loop correction in Lehmann-Kallen form

  • JILIN
  • · Replies 7 ·
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7

Graduate Unitary Operator Inverse Transformation: Solving for a_m

  • Hazzattack
  • · Replies 14 ·
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14

Graduate Understanding Energy and Frequency in Rotation Spectra

  • unscientific
  • · Replies 5 ·
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5

Graduate Understanding Standing Waves in Hydrogen with Animation and Quantum Mechanics

  • bobie
  • · Replies 4 ·
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4

Graduate Understanding Spin-Orbit Interaction's Impact on Electron Energy Levels

  • bobie
  • · Replies 4 ·
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4

Graduate The double slit experiment question?

  • masky007
  • · Replies 4 ·
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4

Graduate Collapsing the wavefuntion to an Energy Eigenfunction?

  • mkarydas
  • · Replies 3 ·
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3

Graduate Are Lasers Truly Examples of Quantum Coherent States?

  • Xyius
  • · Replies 18 ·
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18

Graduate Laplace-Runge-Lenz vector problem

  • wantommy
  • · Replies 2 ·
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Graduate Form of Solution to Schrodinger Equation

  • mrrelativistic
  • · Replies 5 ·
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Graduate Heisenberg's Uncertainty or hidden variable

  • JohnLuck
  • · Replies 9 ·
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9

Graduate Completeness of the eigenfunctions (Which vectorspace?)

  • Runei
  • · Replies 2 ·
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Graduate One dimensional problems. More particles.

  • LagrangeEuler
  • · Replies 5 ·
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Graduate Perturbation theory (the math)

  • Runei
  • · Replies 5 ·
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5

Graduate What is the average value of an observable in a quantum system?

  • LagrangeEuler
  • · Replies 7 ·
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Graduate Phase factors with eigenstates

  • Hazzattack
  • · Replies 8 ·
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8

Undergrad Activity of photon during wavelegnth duration

  • acesuv
  • · Replies 3 ·
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3

Graduate How Can Mixed States Be Prepared Beyond Decoherence?

  • naima
  • · Replies 17 ·
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Graduate Is determinism truly at play in this scenario?

  • craigi
  • · Replies 54 ·
2
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Graduate Why do two people see the same experimental results?

  • wmikewells
  • · Replies 38 ·
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Graduate All eigenvalues of a Hermitian matrix are real

  • Isaac.Wang88
  • · Replies 3 ·
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Graduate Fermi's Golden Rule: non-sinusoidal [itex]t\to\infty[/itex]

  • MisterX
  • · Replies 6 ·
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Graduate Graph States for Quantum Secret Sharing

  • limarodessa
  • · Replies 1 ·
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Graduate Didn't understand what Sakurai meant by this.

  • M. next
  • · Replies 6 ·
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Graduate Exact S-matrix for potential scattering

  • alemsalem
  • · Replies 1 ·
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Graduate Diffraction accompanied with photoelectric effect

  • bgq
  • · Replies 6 ·
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Graduate C-G coefficients by matrix method

  • M. next
  • · Replies 16 ·
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Graduate The Relationship Between Wavelength and Amplitude of Photons and Electrons

  • bobie
  • · Replies 27 ·
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27

Graduate Mean Occupation Number of Non-interacting quantum fluids

  • unscientific
  • · Replies 3 ·
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3

Graduate Name of this relation, and struggle proving it.

  • M. next
  • · Replies 3 ·
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3

Graduate What's up with the absorptive quantum eraser?

  • ab_gladsaxe
  • · Replies 5 ·
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5

Graduate QFT (derivative the covariant and contravariant fields)

  • aams
  • · Replies 10 ·
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Graduate Spin as internal angular momentum

  • Idoubt
  • · Replies 4 ·
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Graduate Quantum Physics Science Advanced Project

  • The12thDoctor
  • · Replies 8 ·
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8

Graduate Joint distribution of position and momentum

  • atyy
  • · Replies 6 ·
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Graduate Understanding Spin Magnetic Field and its Direction in Relation to Charge Spin

  • M.Kalai vanan
  • · Replies 1 ·
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Graduate Can Quantum States Be Deduced from a Density Matrix?

  • suma
  • · Replies 7 ·
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7

Graduate Definition of Pointer in Measurement

  • SheikYerbouti
  • · Replies 2 ·
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Graduate Simultaneous measuring of two operators

  • Caulfield
  • · Replies 4 ·
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Graduate Fourier transform. Impulse representation.

  • LagrangeEuler
  • · Replies 1 ·
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Graduate Is the Momentum Operator Hermitian in Quantum Mechanics?

  • dyn
  • · Replies 14 ·
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14

Graduate Can Photon States Be Represented as Column Vectors in Quantum Mechanics?

  • suma
  • · Replies 1 ·
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Graduate Changing the Hamiltonian without affecting the wave function

  • Isaac.Wang88
  • · Replies 1 ·
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1

Graduate Understanding Normal Ordering: Anhillation and Creation Operators Explained

  • kashokjayaram
  • · Replies 3 ·
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3

Graduate Quantum Mechanics without Measurement

  • stevendaryl
  • · Replies 286 ·
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Graduate Partition Function, Grand Potential

  • unscientific
  • · Replies 2 ·
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2

Graduate Calculating Probability of Field States in QFT

  • GarageDweller
  • · Replies 8 ·
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8

High School Are electrons particles or waves?

  • sharnrock
  • · Replies 18 ·
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18

Graduate Signs in the Field-Theoretic Euler-Lagrange Equation

  • Xezlec
  • · Replies 2 ·
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2

Graduate What is the lowest rotational energy level for a diatomic molecule?

  • spaghetti3451
  • · Replies 2 ·
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2

Graduate Why is the conductance quantized?

  • wdlang
  • · Replies 2 ·
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Graduate My understanding of Quantum Fields [Please correct me if I'm wrong]

  • themadquark
  • · Replies 5 ·
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5

Graduate Normal ordering versus no normal ordering

  • geoduck
  • · Replies 14 ·
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14

Graduate Question on the 2-dim representation of the Lorentz group

  • Kontilera
  • · Replies 6 ·
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6

Graduate How Do Eigenvalues Relate to Quantum Mechanics and Classical Physics?

  • CSOleson
  • · Replies 6 ·
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6

Graduate What Causes Amplitude Changes in Light During Surface Interaction in QED?

  • NewChemTeache
  • · Replies 1 ·
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1

Graduate Entanglement Swapping Superluminal Communication

  • burke142
  • · Replies 1 ·
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1

Graduate The Extra Energy of a Doppler-Shifted Photon: Where Does it Go?

  • Zak
  • · Replies 2 ·
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2

Undergrad Nuclear Rotation: Electrons & Nucleus Vibration in Atom

  • M.Kalai vanan
  • · Replies 2 ·
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2

Graduate What are some examples of non-commutating observables in quantum mechanics?

  • anorlunda
  • · Replies 6 ·
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6

Graduate Destructive interference with different path lengths?

  • fleem
  • · Replies 8 ·
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8

Graduate What is the first and second quantization?

  • Gabriel Maia
  • · Replies 3 ·
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3

Graduate Calc Commutator in Infinitely Potential Well: Is it Possible?

  • LagrangeEuler
  • · Replies 35 ·
2
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Undergrad Heisenberg's Uncertainty Principle

  • X_Art_X
  • · Replies 13 ·
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13

Graduate On the classical action in Feynman approach

  • metroplex021
  • · Replies 3 ·
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3

Graduate 'Largest' Schrodinger cat states created to date?

  • Gwinterz
  • · Replies 2 ·
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2

Graduate Expectation value for momentum operator using Dirac Notation

  • sddang
  • · Replies 12 ·
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12

Graduate Relativistic Quantum Mechanics?

  • Zak
  • · Replies 7 ·
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7

Graduate What is the use of Dirac delta function in quantum mechanics?

  • manimaran1605
  • · Replies 8 ·
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8

Graduate Classical wavelength versus wavefunction

  • idea2000
  • · Replies 1 ·
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1

Graduate Exotic particles from Casimir?

  • nomadreid
  • · Replies 1 ·
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1

Graduate Linear superposition. Measurments.

  • LagrangeEuler
  • · Replies 3 ·
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3

Graduate Explaining linear spectroscopy from first principles

  • photon stew
  • · Replies 7 ·
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7

Graduate How do you rotate an electron 360 degrees?

  • dsoodak
  • · Replies 14 ·
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14
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2

Graduate Casimir plates prevent photon existence only perpendicular to them?

  • Edi
  • · Replies 6 ·
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6

Graduate Classic Oscillator: Understanding Matrix Form with Shankar

  • chimay
  • · Replies 3 ·
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3

Graduate Quantum States and ladder operator

  • kashokjayaram
  • · Replies 13 ·
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13

Graduate Entangled photons in double slit experiment

  • 0xDEAD BEEF
  • · Replies 5 ·
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5

Graduate Are coordinate operators Hermitian?

  • Heisenberg
  • · Replies 3 ·
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3

Graduate Commutation relation to find Sx, Sy

  • M. next
  • · Replies 7 ·
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7

Graduate Acceleration. Infinite potential well.

  • LagrangeEuler
  • · Replies 4 ·
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