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

Undergrad What's the importance of the squared of the angular momentum?

  • annaphys
  • · Replies 4 ·
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4

Undergrad What is the significance of 54 volts in the Davidson Germer Experiment?

  • Nikhil Rajagopalan
  • · Replies 3 ·
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3

High School Entanglement - lack of "symmetry" in no-hidden variables explanation

  • mgkii
  • · Replies 44 ·
2
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44

High School Understanding Phase Terminology in Wave Functions

  • etotheipi
  • · Replies 9 ·
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9

Graduate Quantum biology - photosynthesis

  • Amin48
  • · Replies 3 ·
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3

High School How does the observed version of the double slit get by without math?

  • DamonL
  • · Replies 15 ·
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15

Undergrad Entanglement setup that shouldn't allow for the transmission of info

  • entropy1
  • · Replies 2 ·
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2

Undergrad Commutator's Matrix representation

  • Javier2808
  • · Replies 11 ·
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11

Undergrad What is the cross section of a graviton?

  • KurtLudwig
  • · Replies 18 ·
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18

Graduate Annihilation creation operators in case of half H.oscillator

  • SUVAM ROY
  • · Replies 14 ·
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14

Undergrad Decoupling of angular momentum

  • kelly0303
  • · Replies 4 ·
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4

Graduate What is the Corrected Heisenberg Limit for Phase Estimation Measurements?

  • PeterDonis
  • · Replies 3 ·
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3

Undergrad Topological quantum physics - spin statistics

  • Replusz
  • · Replies 1 ·
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1

High School Where do virtual particles come from?

  • Fiziqs
  • · Replies 9 ·
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9

Undergrad Why Does Equation (5) in Bell's Paper Use < σ⋅a > = 1 - 2θ'/π?

  • quiteconfused
  • · Replies 2 ·
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2

Undergrad Will thermal disturbance change an atom's spin?

  • univector
  • · Replies 5 ·
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5

Undergrad Vector addition in spin orbit coupling

  • kelly0303
  • · Replies 7 ·
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7

Undergrad Why Won't Observation in a 2 Slit Experiment Cause 1 Slit Diffraction?

  • Flamel
  • · Replies 39 ·
2
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39

Undergrad Why do we observe an electron both as a wave and as a particle ?

  • Leonardo Bittar
  • · Replies 3 ·
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3

High School Multiple Sequential Delayed Choice Experiment

  • knightwing
  • · Replies 5 ·
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5

Graduate Langevin equation - derivative of random force?

  • SchroedingersLion
  • · Replies 8 ·
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8

Undergrad Energy of massless particles before electroweak symmetry breaking

  • Ranku
  • · Replies 2 ·
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2

High School Interesting Book On The History Of QM And Einstein's Role

  • bhobba
  • · Replies 7 ·
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7

Undergrad How can a photon "stimulate emission" if it really does (Einstein coefficients)

  • freetheparticle
  • · Replies 11 ·
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11

High School Detecting a photon passing through a slit without destroying it?

  • Cato
  • · Replies 4 ·
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4

Undergrad Gauge Transformations and the Covariant Derivative

  • PeroK
  • · Replies 2 ·
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2

Undergrad Does classical mechanics apply to the quantum world at all?

  • Galactic explosion
  • · Replies 26 ·
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26

Undergrad Use of the Beam Splitter Operator

  • BeyondBelief96
  • · Replies 4 ·
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4

Undergrad Photon Bell Experiment, what happens in a single case?

  • KeesDeVries
  • · Replies 4 ·
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4

Undergrad Scatter radiation and film fogging

  • Asmaa Mohammad
  • · Replies 1 ·
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1

Undergrad Can on-shell virtual particles appear in Feynman diagrams?

  • asimov42
  • · Replies 7 ·
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7

Undergrad Is a bipartite system necessary for the proof of the PBR theorem?

  • greypilgrim
  • · Replies 2 ·
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2

Undergrad What do we do with the massive scalar quantum field in QFT?

  • PeroK
  • · Replies 15 ·
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15

Undergrad Why induction requires a magnetic material to produce a current

  • Wille
  • · Replies 7 ·
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7

High School Compton Effect -- Why is the electron considered to initially be at rest?

  • Viona
  • · Replies 4 ·
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4

Undergrad Physical meaning of ##\psi_1(x)\hat{A}\psi_2(x)##

  • amjad-sh
  • · Replies 11 ·
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11

Graduate Diagonalization of 2x2 Hermitian matrices using Wigner D-Matrix

  • Max1
  • · Replies 4 ·
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4

Graduate Two Different Fock State Inputs into a Beam Splitter

  • BeyondBelief96
  • · Replies 1 ·
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1

Undergrad Why is blackbody radiation continuous while atomic emission is discrete?

  • Viona
  • · Replies 2 ·
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2

Undergrad How is the information of a change in position of a star transmitted?

  • KurtLudwig
  • · Replies 2 ·
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2

Graduate When should we use the Langevin equation and when should use Fokker-Planck

  • Sciencestd
  • · Replies 4 ·
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4

Graduate S-matrix expansion and Wick's theorem

  • Gaussian97
  • · Replies 1 ·
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1

Undergrad Field Renormalization vs. Interaction Picture

  • maline
  • · Replies 39 ·
2
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39

Graduate Photoelectric effect at metal junctions

  • technano
  • · Replies 4 ·
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4

Graduate Are complex numbers necessary in quantum mechanics?

  • Demystifier
  • · Replies 219 ·
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219

Undergrad Photon interference and path differences

  • kurt101
  • · Replies 18 ·
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18

Undergrad Does Bell's theorem imply other Lorentz transformations?

  • jk22
  • · Replies 13 ·
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13

High School Layman's question re quantum entanglement

  • Tom Nicholson
  • · Replies 12 ·
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12

Undergrad Momentum-Position vs. Energy-Time Uncertainty Relations

  • Logic314
  • · Replies 10 ·
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10

Graduate What did Hans Bethe think of von Neumann's quantum logic?

  • Suekdccia
  • · Replies 1 ·
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1

Undergrad Why do electrons emit light when solids are heated to glowing?

  • Wille
  • · Replies 11 ·
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11

Graduate Understanding Harmonic oscillator conventions

  • Djawu
  • · Replies 6 ·
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6

Undergrad What Is the Physical Meaning of Atomic Particle 'Spin'?

  • cmb
  • · Replies 15 ·
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15

Undergrad Collapse of the wave function under simultaneous measurement

  • Philippe H
  • · Replies 2 ·
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2

High School Quantum mechanical model of an atom

  • Frigus
  • · Replies 7 ·
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7

Undergrad Master` Equation for the Penrose-Diosi wavefunction collapse

  • Agrippa
  • · Replies 2 ·
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2

Undergrad Photon occupation numbers in relation to the 4-potential

  • olgerm
  • · Replies 26 ·
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26

Undergrad What is SR transformarion for bispinor?

  • olgerm
  • · Replies 49 ·
2
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49

Undergrad General Implications of the Double-Slit Experiment

  • lifeonmercury
  • · Replies 1 ·
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1

High School The Virtue of Individual Perception RE: Wavefunction Collapse

  • Denselight93
  • · Replies 2 ·
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2

Undergrad Let me Know What you Think of This Toy Theory

  • KyleSingh
  • · Replies 3 ·
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3

Undergrad Is the energy of a burst of light the sum of the energy of each photon?

  • Aaron121
  • · Replies 28 ·
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28

Undergrad Trying to Generate Entangled Photons

  • Strange_matter
  • · Replies 6 ·
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6

Graduate Unitary representations of Lie group from Lie algebra

  • leo.
  • · Replies 5 ·
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5

Undergrad Calculating group representation matrices from basis vector/function

  • pellis
  • · Replies 6 ·
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6

High School How does measuring particle A affect particle B in entanglement?

  • Andyhs
  • · Replies 11 ·
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11

Graduate The cnot with outer product control qubit

  • Galaxion
  • · Replies 1 ·
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1

Undergrad How Would Afshar's Experiment Affect Entanglement?

  • Erik Ayer
  • · Replies 2 ·
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2

Undergrad Exclusion principle and the distance between two particles

  • dRic2
  • · Replies 3 ·
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3

Undergrad Polarization and Stimulated Emission

  • Erik Ayer
  • · Replies 20 ·
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20

Undergrad Is a Particle Simply the Manifested Kinetic Energy of Its Quantum Field?

  • Tiptoeingelephants
  • · Replies 2 ·
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2

Undergrad Minimum number of cycles in a short pulse laser

  • Uchida
  • · Replies 6 ·
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6

Graduate Dirac Field quantization and anti-commutator relation

  • sakh1012
  • · Replies 1 ·
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1

Undergrad Is there a reason eigenvalues of operators correspond to measurements?

  • gsingh2011
  • · Replies 2 ·
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2

Undergrad The HOM Effect, Path Entanglement, and Generation

  • Erik Ayer
  • · Replies 5 ·
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5

Undergrad Dispersive approximation (limit) in the Jaynes-Cummings Model

  • thephysicsboy1998
  • · Replies 1 ·
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1

Graduate Hermitian operators and matrices in quantum mechanics

  • Greg Bernhardt
  • · Replies 1 ·
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1

Graduate Definition of Expectation Value (EV)

  • Greg Bernhardt
  • · Replies 1 ·
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1

Undergrad Hamiltonian Commutation Question

  • Diracobama2181
  • · Replies 6 ·
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6

High School Is Bell's inequality Lorentz invariant?

  • jk22
  • · Replies 2 ·
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2

High School Notion of a zero dimensional point particle?

  • Nickyv2423
  • · Replies 4 ·
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4

Graduate First Chip-to-Chip Quantum Teleportation

  • Tom.G
  • · Replies 3 ·
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3

Graduate Does Dim Reg really avoid a photon mass?

  • maline
  • · Replies 10 ·
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10

High School Backscattering of photons in dim = 1

  • Heidi
  • · Replies 3 ·
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3

Undergrad Why doesn't rank 1 tensor acting on spin-1/2 produce rank 3/2 terms?

  • Malamala
  • · Replies 2 ·
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2

High School Neutron Decay Outside of a Nucleus Near Absolute Zero

  • Chris Nimmons
  • · Replies 3 ·
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3

Graduate Measurements of multipartite entanglement

  • Danny Boy
  • · Replies 1 ·
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1

Undergrad Imagining the EPR paradox/quantum entanglement

  • tommmyyyy
  • · Replies 6 ·
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6

Undergrad Entanglement after measurement

  • nomadreid
  • · Replies 16 ·
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16

Undergrad The construction of particles in QFT

  • ilper
  • · Replies 70 ·
3
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70

Graduate Trace of a product of Dirac Matrices in a Fermion loop

  • RicardoMP
  • · Replies 5 ·
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5

Undergrad How does a quantum computer work?

  • Johnny5454
  • · Replies 7 ·
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7

Undergrad How do momentum eigenstates have the form e^(2πix) and relate to conservation?

  • Zala Jaydevsinh
  • · Replies 1 ·
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1

Undergrad Why Do We Have The Effect Of Spontaneous Emission And Absorption

  • bhobba
  • · Replies 2 ·
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2

Undergrad What are the degrees of freedom of a quark?

  • stephen weber
  • · Replies 14 ·
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14

Undergrad Wave function of a laser beam?

  • DEvens
  • · Replies 6 ·
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6

High School Do photons bunch up at an interface? Can they lase (laze?)

  • ImaO
  • · Replies 17 ·
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17

Undergrad Can a simulation hypothesis simulate quantum physics?

  • Endypanzer
  • · Replies 10 ·
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10

Undergrad Simulation Hypothesis: Quantum Computer Modeling

  • Johnny5454
  • · Replies 2 ·
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2

Graduate Vacuum energy density after spontaneous symmetry breaking

  • Geonaut
  • · Replies 5 ·
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5