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 Is renormalization the ideal solution?

  • Geonaut
  • · Replies 57 ·
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Graduate Hamiltonian background magnetic field, perturbed by electric field

  • binbagsss
  • · Replies 2 ·
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Undergrad Stern-Gerlach "interferometry"

  • WWCY
  • · Replies 10 ·
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High School Quantum computer vs supercomputer performance

  • Bob Walance
  • · Replies 8 ·
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8

Undergrad What determines photon frequency when absorbed and emitted by electrons?

  • dsaun777
  • · Replies 19 ·
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Undergrad The expected value (or mean) of X

  • peace
  • · Replies 6 ·
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Graduate Time Dependent Perturbation of Harmonic Oscillator

  • Diracobama2181
  • · Replies 1 ·
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Graduate What is the definition of 'ground state',considering H- ion = -14.35eV

  • cmb
  • · Replies 2 ·
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Undergrad Griffiths notation for spin expectation values with Re and Im

  • kmm
  • · Replies 9 ·
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Undergrad Dirac notation and calculations

  • electrogeek
  • · Replies 9 ·
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9

Undergrad What do the commutation/anti-commutation relations mean in QFT?

  • moss
  • · Replies 18 ·
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18

High School Roger Penrose's need for a physics Grey area

  • edmund cavendish
  • · Replies 2 ·
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Undergrad Quantum number and group theory

  • Dalor
  • · Replies 10 ·
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10

Undergrad Relationship between EM and matter fields in QED

  • CSnowden
  • · Replies 19 ·
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Undergrad Probability flux inside the finite potential barrier

  • Haynes Kwon
  • · Replies 1 ·
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Undergrad Fourier Transform of the Wave function

  • Haynes Kwon
  • · Replies 1 ·
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High School Normalizability of continuous and discrete spectrum

  • Sunny Singh
  • · Replies 3 ·
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Undergrad Proving the anticommutator of canonical momentum vanishes in the Pauli equation

  • Airton Rampim
  • · Replies 4 ·
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High School Can a quantum particle be simulated on a classical computer?

  • TheQuestionGuy14
  • · Replies 1 ·
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High School What is the largest object that exhibits Quantum properties

  • Suppaman
  • · Replies 18 ·
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18

Undergrad Wave function for a helium atom

  • olgerm
  • · Replies 19 ·
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19

Undergrad Parity and Interactions: Misreading or Misunderstanding?

  • KevinMcHugh
  • · Replies 2 ·
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Graduate Fock spaces and inequivalent ccr representations

  • Heidi
  • · Replies 5 ·
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Graduate Overlap of nth QHO excited state and momentum-shifted QHO ground state

  • HBHSU
  • · Replies 1 ·
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Undergrad Giving mass to other particles?

  • Xforce
  • · Replies 4 ·
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Undergrad Calculating a particular amplitude with Feynman diagrams

  • Ringo Hendrix
  • · Replies 2 ·
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Graduate Difference between russel-saunders-coupling and spin-orbit-coupling

  • JanSpintronics
  • · Replies 3 ·
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Undergrad Time Delay Information Transfer with Entangled Particles

  • jackmiller2003
  • · Replies 10 ·
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Undergrad Energy at classically forbiden positions

  • DaTario
  • · Replies 26 ·
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Undergrad Observation = interaction, question from a dummy

  • CuriousCop
  • · Replies 10 ·
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Undergrad Why do raising operators for spin 1/2 have a factor of ℏ?

  • aliens123
  • · Replies 2 ·
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High School Does QED explain light reflection through photon absorption and re-emission?

  • fbs7
  • · Replies 14 ·
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Undergrad Can gravitons help unify quantum mechanics and general relativity?

  • Physics4Eva
  • · Replies 2 ·
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Undergrad When can the Klein-Gordon Equation be used for a photon?

  • LarryS
  • · Replies 11 ·
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Undergrad Entanglement/correlations in time

  • WWCY
  • · Replies 1 ·
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Graduate Measurements and electroweak gauge invariance/transformations

  • Michael Price
  • · Replies 2 ·
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Graduate What is the solution for two electrons on a sphere?

  • bob012345
  • · Replies 50 ·
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High School Photons as bullets at 10 trillion FPS (frames per second)

  • EPR
  • · Replies 14 ·
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Graduate Canonical quantization of Electrodynamics: physical intuition ?

  • maajdl
  • · Replies 3 ·
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High School Can a wavelength be smaller than a Planck length?

  • sqljunkey
  • · Replies 7 ·
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High School Photon Continuity in Double-Slit Experiment

  • jeremyfiennes
  • · Replies 80 ·
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High School Is the Velocity of Electron Spin Calculable Using Classical Models?

  • Dilema
  • · Replies 14 ·
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Undergrad It seems QFT and QM contradict with each other?

  • fxdung
  • · Replies 15 ·
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Graduate Increase of coherent length in stimulated emission

  • DaTario
  • · Replies 19 ·
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Undergrad Simplifying bilinear product with sigma matrices and epsilon tensors

  • hamad12a
  • · Replies 5 ·
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5

High School Can entangled particle pairs be measured at the same time?

  • Quantum Alchemy
  • · Replies 15 ·
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Undergrad Why is the position of a massive particle not blurred?

  • fxdung
  • · Replies 9 ·
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9

Undergrad Why is position just a label in QFT?

  • LarryS
  • · Replies 6 ·
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6

Undergrad Bracket VS wavefunction notation in QM

  • olgerm
  • · Replies 82 ·
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Graduate Conservation of Quantum Information

  • nateHI
  • · Replies 26 ·
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26

Undergrad How to calculate the Lamb Shift in Hydrogen?

  • zincshow
  • · Replies 1 ·
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High School Is Human Height Ever Exactly Pi Feet?

  • batmelon
  • · Replies 5 ·
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5

Undergrad Spatial derivative of a two-particle Hamiltonian with density matrix dependence

  • LeeT
  • · Replies 1 ·
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Undergrad Two Photon Sagnac Source

  • Erik Ayer
  • · Replies 5 ·
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5

Undergrad Mach-Zender-Interferometer with polarizers

  • Sonderval
  • · Replies 8 ·
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8

Undergrad Notion of a "clock" in Quantum Mechanics

  • WWCY
  • · Replies 4 ·
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4

Graduate How do entanglement experiments benefit from QFT (over QM)?

  • DrChinese
  • · Replies 473 ·
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Undergrad Why is a resonant frequency assumed in blackbody radiation?

  • kelly0303
  • · Replies 8 ·
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8

Graduate Extra terms in the Action in Zee chapter 1.3?

  • looseleaf
  • · Replies 2 ·
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2

Undergrad Why simultaneous detection of wave and particle nature is not possible

  • Ablaze_
  • · Replies 8 ·
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8

Undergrad Why does the square of the amplitude of a wave function represent P?

  • Haynes Kwon
  • · Replies 3 ·
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3

High School Does a field's vacuum density violate conservation of energy?

  • TheQuestionGuy14
  • · Replies 29 ·
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29

Undergrad Conservation of energy and measurement problem

  • entropy1
  • · Replies 3 ·
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3

High School How to obtain state vector for polarised light

  • etotheipi
  • · Replies 6 ·
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6

Undergrad Complementarity Of One- And Two-Particle Interference

  • Erik Ayer
  • · Replies 2 ·
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2

Undergrad How to get the wavefunction of a single particle in QFT?

  • DoobleD
  • · Replies 2 ·
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Undergrad Dark Matter and quantum observable

  • new6ton
  • · Replies 1 ·
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High School Is classical physics an approximation of quantum physics?

  • new6ton
  • · Replies 21 ·
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Undergrad Wave function of a scattered particle and cross section

  • dRic2
  • · Replies 8 ·
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8

Graduate Do the time and normal ordering operators commute?

  • QFT1995
  • · Replies 11 ·
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11

Graduate Gauge breaking and Faddeev-Popov ghost particles

  • Michael Price
  • · Replies 46 ·
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Undergrad Does downconversion cause pump photon wavefunction collapse?

  • Erik Ayer
  • · Replies 8 ·
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8

Graduate Why are loop diagrams O(h) corrections to tree level amplitudes?

  • PGaccount
  • · Replies 2 ·
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2

Undergrad Physical Meaning of a Quantum Field

  • Bobjoesmith
  • · Replies 5 ·
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5

Undergrad Can a 4x4 matrix act on a 2x2 matrix in a specific way?

  • Replusz
  • · Replies 4 ·
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4

Graduate Bosonic Field operator in this exponential

  • QFT1995
  • · Replies 2 ·
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2

Undergrad Bohr model for electron energy states

  • Iceking20
  • · Replies 4 ·
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4

High School Quantum Gravity and Special Relativity

  • Meruem
  • · Replies 2 ·
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2

High School Interaction of light with atoms

  • jeremyfiennes
  • · Replies 9 ·
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9

Undergrad How does the expectation value of the spin operator evolve over time?

  • Garlic
  • · Replies 3 ·
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3

Undergrad Are quantum states always vectors in Hilbert space?

  • nomadreid
  • · Replies 6 ·
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6

Graduate Theoretical status of the Landauer Principle

  • Prathyush
  • · Replies 12 ·
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12

Graduate Why are most molecules in the singlet state instead of the triplet state?

  • hariharan venkatasu
  • · Replies 4 ·
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4

Undergrad Can two particles be in the same place at the same time?

  • JamesN
  • · Replies 2 ·
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2

Undergrad "Dumb" question : is there an upper bound on the energy of a photon?

  • s00mb
  • · Replies 3 ·
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3

High School Is quantum entanglement a four dimensional force?

  • Meruem
  • · Replies 5 ·
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5

Undergrad What happens to an electron's frequency during absorption of a photon?

  • Iceking20
  • · Replies 4 ·
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4

Graduate Derivative of a Lorentz-Transformed Field

  • looseleaf
  • · Replies 2 ·
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2

Undergrad Rydberg Equation: Physics and Beyond

  • Iceking20
  • · Replies 5 ·
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5

High School Do electrons accelerate during energy state transitions?

  • Iceking20
  • · Replies 34 ·
2
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34

Graduate Can Work Be Defined for a Quantum System with a Time-Dependent Hamiltonian?

  • Prathyush
  • · Replies 11 ·
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11

Undergrad Solving a quantum harmonic oscillator using quasi momentum

  • Prathyush
  • · Replies 1 ·
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1

Graduate Correlation functions of quantum Ising model

  • Danny Boy
  • · Replies 1 ·
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1

High School Quantum radar and its implications

  • GTOM
  • · Replies 3 ·
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3

Undergrad Schrodinger equation for a free particle in 3d space

  • GeolPhysics
  • · Replies 6 ·
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6

Undergrad Does this system have runaway solutions?

  • srallaba
  • · Replies 10 ·
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10

Graduate Delta function with negative subscripts in P&S

  • looseleaf
  • · Replies 16 ·
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16

Undergrad Am I crazy or is my book wrong?

  • yjl
  • · Replies 5 ·
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5

Undergrad What would happen if wavelength could go higher than gamma rays

  • Iceking20
  • · Replies 8 ·
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8

Undergrad Attractive van der Waals force between similar atoms/molecules

  • Swamp Thing
  • · Replies 10 ·
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