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

High School Is angular momentum of a quantum object, metaphorical?

  • bland
  • · Replies 28 ·
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28

Undergrad Relationship Between Hermitian and Symmetric Matrices

  • math_major_111
  • · Replies 3 ·
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3

Undergrad Why do the alternatives separate from each other?

  • Erland
  • · Replies 7 ·
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7

Undergrad QFT for the Gifted Amateur Question (3)

  • 43arcsec
  • · Replies 1 ·
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1

High School What theorem forbids communication between branches in quantum mechanics?

  • fanieh
  • · Replies 9 ·
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9

Graduate Quantized E field, Coulomb Gauge with Interactions

  • MisterX
  • · Replies 8 ·
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8

High School What is information?

  • Einstein's Cat
  • · Replies 5 ·
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5

Undergrad Ensembles and density matrices - I don't get it

  • Erland
  • · Replies 10 ·
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10

Undergrad The wave function is an exponential function, if I plot the

  • LSMOG
  • · Replies 3 ·
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3

Undergrad Test of Bell's Theorem: Experiments Beyond Polarization

  • Dadface
  • · Replies 6 ·
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6

High School Can a hydrogen atom be in a superposition before photon emission?

  • Shing Ernst
  • · Replies 10 ·
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10

High School Quantum Physics -Double Slit Delayed Observation

  • Bill_W
  • · Replies 13 ·
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13

High School Can Measuring Momentum Make a Marble's Position Vanish?

  • fanieh
  • · Replies 6 ·
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6

High School Does tunneling affect the energy of a particle in a finite box?

  • houlahound
  • · Replies 3 ·
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3

Graduate I've tried to read the reason for using Fourier transform

  • LSMOG
  • · Replies 5 ·
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5

High School Electron Diffraction and the DeBroglie Wavelength

  • Guest432
  • · Replies 1 ·
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1

Graduate Does Quantum Foam Influence the Gravity of the Universe?

  • Ginosko
  • · Replies 1 ·
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1

High School The moment we observe superposition

  • Taskle
  • · Replies 14 ·
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14

Graduate Mandelstam Variables for 2->2 Scattering with Equal Masses in CoM Frame

  • spaghetti3451
  • · Replies 32 ·
2
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32

High School How does electron microscopy exploit wave/particle duality?

  • Guest432
  • · Replies 2 ·
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2

Undergrad Can someone explain this picture to me?

  • Armando Valle
  • · Replies 3 ·
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3

Undergrad Finite difference method for Schrödinger equation

  • aaaa202
  • · Replies 3 ·
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3

Undergrad Quantum thermodynamics of single particle

  • Konte
  • · Replies 13 ·
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13

Undergrad Is vacuum energy infinite? If it is, how and why?

  • Noduagga
  • · Replies 5 ·
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5

High School Can quantum mechanics be derived from deeper principles?

  • kochanskij
  • · Replies 2 ·
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2

High School Could spin be a combination of magnetic monopoles?

  • Wminus
  • · Replies 11 ·
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11

High School Can quantum teleportation transmit information?

  • TJung
  • · Replies 10 ·
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10

High School How Does Quantum Darwinism Relate to the Born Rule and Observer Agreement?

  • cube137
  • · Replies 43 ·
2
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43

Undergrad Bell's Theorem: Understanding Bell's Nonlocality and How it Applies to Photons

  • jk22
  • · Replies 6 ·
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6

Undergrad Role of entanglement in general purpose quantum computing

  • raphampm
  • · Replies 2 ·
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2

High School Is there a minimum wavelength for electromagnetic radiation?

  • afcsimoes
  • · Replies 11 ·
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11

Graduate Is Brute Force the Best Approach to Proving Feynman's Denominator Formula?

  • spaghetti3451
  • · Replies 3 ·
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3

Undergrad Does the electron really spin 720 degrees?

  • Chris Frisella
  • · Replies 71 ·
3
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71

Graduate Spinors in dimensions other than 4

  • spaghetti3451
  • · Replies 3 ·
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3

Undergrad Unified gravity with electroweak through SU(2)xSU(2)xU(1)

  • fxdung
  • · Replies 3 ·
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3

High School What is the Light Constant and Its Relationship to Maxwell's Equations?

  • Ali Abbas
  • · Replies 2 ·
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2

High School Decoherence thought experiment

  • jartsa
  • · Replies 4 ·
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4

High School Is it a myth that serves as motivation for decoherence?

  • zonde
  • · Replies 11 ·
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11

Graduate Particles in quantum field theory

  • A. Neumaier
  • · Replies 16 ·
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16

High School Photoelectric effect and atomic excitation

  • Metals
  • · Replies 3 ·
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3

High School Compton’s experiment vs ordinary mirror

  • exmarine
  • · Replies 8 ·
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8

Undergrad Uncertainty of electron energy based on confinement radius?

  • excalibur313
  • · Replies 2 ·
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2

Undergrad Decoherence and time reversal asymmetry

  • Charlie313
  • · Replies 4 ·
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4

Undergrad Does wavefunction change from photon absorption propagate faster than light?

  • asimov42
  • · Replies 5 ·
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5

High School Does an electron oscillate as it moves through space?

  • LSMOG
  • · Replies 17 ·
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17

Undergrad Problem during finding <x> in p space

  • Shell_E
  • · Replies 4 ·
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4

Undergrad What is the width of a wave packet?

  • RicardoMP
  • · Replies 3 ·
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3

High School Can Particles Really Pop Into Existence from a Vacuum?

  • NewToThis
  • · Replies 26 ·
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26

Undergrad What are spinors and how are they used in physics?

  • Aakash Lakshmanan
  • · Replies 16 ·
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16

Graduate Is Gravity Directly Related to Groupings of Atoms?

  • EsquireWilliam
  • · Replies 9 ·
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9

Undergrad Stationary states -- Boltzmann distribution

  • Konte
  • · Replies 22 ·
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22

High School What Causes Decoherence in Quantum Systems?

  • bluecap
  • · Replies 31 ·
2
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31

Graduate Issue in the electron’s infinite self-energy

  • USeptim
  • · Replies 3 ·
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3

High School States as positive operators of unit trace

  • cube137
  • · Replies 8 ·
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8

Undergrad Square integrable wave functions vanishing at infinity

  • RicardoMP
  • · Replies 4 ·
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4

Undergrad Wavefunction spreading speed in material mediums

  • Gerinski
  • · Replies 1 ·
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1

Undergrad What is the wavelike behavior of an electron in superposition?

  • Kiki
  • · Replies 16 ·
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16

Undergrad Everett on measurements: what does he mean?

  • Erland
  • · Replies 8 ·
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8

Undergrad Two single-photon Fock states vs one two-photon Fock state

  • maxverywell
  • · Replies 25 ·
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25

High School What is the relationship between spin and angular momentum in quantum mechanics?

  • Ontophobe
  • · Replies 5 ·
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5

Undergrad Entangled system pure state or not?

  • bluecap
  • · Replies 80 ·
3
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80

High School Is wave a physical object or its just a model?

  • LSMOG
  • · Replies 12 ·
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12

Undergrad Are renormalizable QFT the ''really renormalizable''?

  • fxdung
  • · Replies 16 ·
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16

High School Why do we say that there is no polarization until it is measured

  • Robin
  • · Replies 7 ·
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7

High School Is dark/vacuum potential energy infinite?

  • Noduagga
  • · Replies 13 ·
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13

Undergrad Why does an electron undergo diffraction?

  • LSMOG
  • · Replies 6 ·
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6

Undergrad Why do we use Complex Wave function?

  • SiuKing666
  • · Replies 3 ·
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3

High School Penrose collapse and Superposition

  • bluecap
  • · Replies 8 ·
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8

Undergrad Is there any operator for momentum in terms of t?

  • Aswin Sasikumar 1729
  • · Replies 3 ·
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3

High School Why does CPT theorem apply to all Lorentz covariant Lagrangians?

  • fxdung
  • · Replies 1 ·
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1

Undergrad Limit to the max size of a Nucleus

  • daniel christ
  • · Replies 7 ·
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7

Undergrad Vanishing Hamiltonian for quantum path integral

  • spaghetti3451
  • · Replies 2 ·
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2

Graduate Feynman rules for a 0-dimensional field theory

  • spaghetti3451
  • · Replies 15 ·
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15

Undergrad Do path integral terms for causally disconnected particles cancel out?

  • asimov42
  • · Replies 6 ·
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6

High School Why do ladder operators give all quantum oscillator states?

  • Mayan Fung
  • · Replies 14 ·
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14

Graduate Function integration of a Gaussian integral

  • spaghetti3451
  • · Replies 1 ·
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1

Graduate Why quantum mechanics looks so different from classical one?

  • Nixom
  • · Replies 27 ·
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27

Graduate How to Calculate Probability using Density Operator?

  • Guilherme Vieira
  • · Replies 5 ·
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5

Undergrad Anderson Localization and general disorder of matter?

  • asimov42
  • · Replies 9 ·
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9

High School Can position eigenstates be considered qubits in quantum computing?

  • bluecap
  • · Replies 11 ·
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11

Undergrad Why does Simon's algorithm need n-1 equations to find the secret string?

  • Aakash Lakshmanan
  • · Replies 1 ·
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1

Undergrad How can you detect which path an electron will take in a double-slit experiment?

  • maka89
  • · Replies 7 ·
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7

Graduate Utility of path integral formulation of quantum mechanics

  • spaghetti3451
  • · Replies 12 ·
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12

Insights Why Is Quantum Mechanics So Difficult? - Comments

  • Greg Bernhardt
  • · Replies 251 ·
9
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251

Undergrad Probability of one-photon loss from a cavity

  • maxverywell
  • · Replies 3 ·
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3

Undergrad Why is the Kinetic Energy Operator Differentiated Twice Instead of Squared?

  • Mayan Fung
  • · Replies 3 ·
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3

High School Question about photocell experiment

  • Clara Chung
  • · Replies 1 ·
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1

High School Does QM allow for entropy decrease of a closed system?

  • Grinkle
  • · Replies 13 ·
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13

Undergrad Why Is the Limit ##\hbar \rightarrow 0## Called the Semiclassical Limit?

  • spaghetti3451
  • · Replies 20 ·
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20

Graduate Where does statistical physics/mechanics fit in with QFT,GR?

  • Indiana
  • · Replies 1 ·
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1

Undergrad Beam in specific photon number state?

  • maxverywell
  • · Replies 7 ·
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7

High School How do you prepare an electron in an atom in a pure state?

  • bluecap
  • · Replies 18 ·
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18

Undergrad Localization of particles and disorder at the quantum level?

  • asimov42
  • · Replies 5 ·
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5

Undergrad Wave particle duality and phonons

  • Collin237
  • · Replies 10 ·
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10

Graduate Projection trick to obtain time-ordered correlator

  • spaghetti3451
  • · Replies 1 ·
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1

Graduate Partition function in quantum field theory

  • spaghetti3451
  • · Replies 6 ·
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6

Graduate Path integral computes time-ordered products

  • spaghetti3451
  • · Replies 1 ·
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1

Undergrad Why can't we use negative values of n in the 1D particle in a box system?

  • Thejas15101998
  • · Replies 5 ·
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5

Graduate 3D oscillator trapped away from centre

  • ftft
  • · Replies 3 ·
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3

Undergrad Why does the Green's function relate to density of states?

  • Nusc
  • · Replies 1 ·
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1