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 Time Dependent Sinusoidal Perturbation Energy Conservation

  • Samama Fahim
  • · Replies 7 ·
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7

Graduate Schmidt decomposition - How do I find the matrix related to the state?

  • Arquimedes
  • · Replies 1 ·
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1

Graduate Constructing the Wigner Function from Measurements of Entangled Photons

  • neils
  • · Replies 5 ·
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5

Undergrad A doubt regarding position representation of product of operators

  • Kashmir
  • · Replies 18 ·
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18

Undergrad Position representation of angular momentum operator

  • Kashmir
  • · Replies 10 ·
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10

High School How Does Photon Polarization Influence Electron State Changes?

  • msumm21
  • · Replies 11 ·
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11

Undergrad Applications of the proposed global quantum network of clocks

  • phoenix-anna
  • · Replies 8 ·
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8

High School Quantum entanglement and energy conservation

  • FR4S3R97
  • · Replies 3 ·
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3

Graduate Possible Ways to reduce Electron field Emission threshold

  • domovinavi
  • · Replies 1 ·
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1

Undergrad Inner products with spherical harmonics in quantum mechanics

  • Salmone
  • · Replies 13 ·
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13

Undergrad Schwartz derivation of the Feynman rules for scalar fields

  • eoghan
  • · Replies 1 ·
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1

Graduate Does partial tracing make us see things that do not occur?

  • Heidi
  • · Replies 7 ·
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7

Graduate Finding the Hermitian generator of a Symplectic transformation

  • andresB
  • · Replies 17 ·
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17

Undergrad Ideas about observing position and momentum at the same time

  • danielgossner
  • · Replies 4 ·
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4

Undergrad Is the moment of the measurement well defined?

  • entropy1
  • · Replies 12 ·
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12

Undergrad Schrodinger equation for N particles in a box

  • Kashmir
  • · Replies 3 ·
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3

Graduate What happens when you commute Sx and Sz in spin operators?

  • Dennmac
  • · Replies 2 ·
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2

Undergrad Form of potential operator of two interacting particles

  • Kashmir
  • · Replies 3 ·
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3

High School Higgs field and nuclear reactions

  • Andrewtv848
  • · Replies 7 ·
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7

Undergrad Basic question on meaning of momentum operator

  • Kashmir
  • · Replies 56 ·
2
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56

High School Special Relativity violation via Quantum Mechanics?

  • thedubdude
  • · Replies 12 ·
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12

Undergrad What is the role of Relativistic QM?

  • fxdung
  • · Replies 40 ·
2
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40

Graduate What do physicists mean when they say photons have a "path"?

  • vanhees71
  • · Replies 119 ·
4
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119

High School Operator as the outcome of a measurement?

  • Heidi
  • · Replies 7 ·
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7

Undergrad Propagation of uncertainty with some constants

  • happyparticle
  • · Replies 8 ·
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8

Undergrad E=hf for massive particles, but which Energy exactly?

  • AlonZ
  • · Replies 5 ·
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5

Undergrad Wavefunction of a free particle has carrier and envelope parts

  • Kashmir
  • · Replies 8 ·
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8

Graduate Question while I study Modern Quantum physics by Sakurai

  • BREAD
  • · Replies 16 ·
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16

Graduate Are Quantum Measurements Truly Special Cases of Unitary Operators?

  • Heidi
  • · Replies 1 ·
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1

Undergrad Probability when measuring a local observable

  • Yan Campo
  • · Replies 1 ·
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1

Undergrad Finding Momentum Mean & Variance from Wavefunction

  • Kashmir
  • · Replies 5 ·
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5

Undergrad The probability density function for the double-slit experiment

  • Ad VanderVen
  • · Replies 19 ·
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19

Undergrad Commutation relations for an interacting scalar field

  • eoghan
  • · Replies 3 ·
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3

Undergrad Determination of entanglement by observing only one photon

  • fluidfcs
  • · Replies 20 ·
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20

Graduate What is the Bell-like Inequality in Classical Physics?

  • Heidi
  • · Replies 6 ·
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6

Graduate Double-Slit Experiment: Momentum & Position

  • Ad VanderVen
  • · Replies 4 ·
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4

High School Virtual photons as force carriers

  • ergo
  • · Replies 29 ·
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29

High School Photon Chirality: Left, Right & Beyond

  • Jeff Root
  • · Replies 7 ·
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7

Undergrad Difficulty in understanding step in Deriving WKB approximation

  • curious_mind
  • · Replies 6 ·
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6

High School In what way does light behave that is incompatible with waves?

  • Ray McDavis
  • · Replies 12 ·
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12

Undergrad What happens to photonic molecules?

  • unsaint32
  • · Replies 5 ·
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5

Undergrad Multiple questions about eigenstates and eigenvalues

  • Sebas4
  • · Replies 3 ·
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3

Graduate Generalized Forces and QED/QCD

  • JohnH
  • · Replies 14 ·
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14

High School Multiple entanglements question

  • brajesh
  • · Replies 22 ·
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22

Undergrad Collapse of wavefunction into a forbidden eigenstate for a free particle

  • Kashmir
  • · Replies 75 ·
3
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75

Undergrad Wave function using the time dependent Schrodinger equation

  • ThiagoSantos
  • · Replies 1 ·
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1

Graduate Noether and the derivative of the Action

  • nemuritai
  • · Replies 3 ·
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3

Undergrad Understanding the Irreducible Solution in Classical Harmonic Oscillators

  • George444fg
  • · Replies 2 ·
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2

Graduate What is the charge range for two N vacancies in a defect crystal?

  • jackwangsg
  • · Replies 1 ·
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1

High School Special Relativity and the Measurement Problem of QM

  • User2022
  • · Replies 7 ·
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7

High School Entangled particle decoherence question

  • brajesh
  • · Replies 4 ·
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4

High School "Quantum Field Theory, as Simply as Possible" upcoming publication

  • StevieTNZ
  • · Replies 27 ·
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27

Undergrad Is the Adjoint of the Position Operator Self-Adjoint?

  • Kashmir
  • · Replies 6 ·
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6

Undergrad Infinite Square Well with an Oscillating Wall (Klein-Gordon Equation)

  • Foracle
  • · Replies 1 ·
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1

Undergrad How to apply potential operator ##V(\hat{x})##

  • Kashmir
  • · Replies 2 ·
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2

Undergrad Potential Energy of an Electron-Nuclei Interaction in DFT

  • Dario56
  • · Replies 1 ·
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1

Graduate Double double slit experiment and path information

  • Heidi
  • · Replies 1 ·
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1

High School What does it mean that a spin 1/2 particle needs two full rotations?

  • vijayantv
  • · Replies 6 ·
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6

Undergrad Kinetic Energy and Potential Energy of Electrons

  • Dario56
  • · Replies 15 ·
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15

Undergrad What is the physical meaning of concurence (quantum information)?

  • Arquimedes
  • · Replies 1 ·
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1

Graduate Electron EM Field as Local Gauge Variation of Electron Matter Field

  • CSnowden
  • · Replies 6 ·
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6

Undergrad Clarification on how bra ket works here

  • Kashmir
  • · Replies 29 ·
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29

Undergrad Probability current density of a stationary state

  • Thomas Rigby
  • · Replies 6 ·
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6

High School Pair production -- Seeking clarification of the explanation

  • Quixotic Larry
  • · Replies 4 ·
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4

Undergrad Can Spinors Be Represented as Square Roots of Vectors in Clifford Algebra?

  • Gerenuk
  • · Replies 2 ·
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2

Graduate Probabilities of couples of impacts - Bob and Alice and Young experiment

  • Heidi
  • · Replies 16 ·
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16

Undergrad Can we accurately predict the properties of gold?

  • bland
  • · Replies 16 ·
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16

Graduate QED Formulation with Massive Photon Fields

  • M91
  • · Replies 3 ·
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3

Undergrad Can a Path Integral Formulation for Photons Start from a Massless Premise?

  • gerald V
  • · Replies 3 ·
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3

Undergrad Odds of getting pairs -- QM version

  • anuttarasammyak
  • · Replies 1 ·
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1

Undergrad Why Are There So Few Quantum Time Machine Models?

  • avpol
  • · Replies 13 ·
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13

Undergrad Definition of magnetic moment in quantum mechanics

  • Kashmir
  • · Replies 6 ·
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6

Undergrad Does it make sense to speak about the Grandfather paradox in QM?

  • jordi
  • · Replies 3 ·
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3

Undergrad Hamiltonian of a particle in a magnetic field

  • Kashmir
  • · Replies 10 ·
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10

Graduate Majorana representation of higher spin states

  • fsh26
  • · Replies 1 ·
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1

Graduate Why Is Dissociation Rate Proportional to Current Raised to the Power of N?

  • Piki
  • · Replies 1 ·
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1

Graduate Definition of finite size, radiative and weak magnetism corrections

  • angweieng
  • · Replies 3 ·
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3

High School Does the Schrödinger Equation Imply a Deterministic Universe?

  • Physics Slayer
  • · Replies 4 ·
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4

Graduate Entangled particles in curved spacetime

  • Heidi
  • · Replies 4 ·
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4

Undergrad Exact dynamics of spin in varying magnetic field

  • KDPhysics
  • · Replies 1 ·
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1

Graduate About Ruling Out Real-Valued Standard Formalism of Quantum Theory

  • Haorong Wu
  • · Replies 20 ·
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20

Undergrad Quantum Mechanics without time?

  • entropy1
  • · Replies 9 ·
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9

Undergrad Projection postulate and the state of a system

  • Kashmir
  • · Replies 9 ·
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9

Undergrad Informational Interpretation of quantum mechanics?

  • Mgt3
  • · Replies 2 ·
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2

Undergrad Spin, pseudo-spin or whatelse? (cavity)Polariton polarimetry question

  • dchafatinos
  • · Replies 4 ·
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4

Undergrad The determination of a particle's spin

  • Randall71284
  • · Replies 4 ·
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4

High School Can probability waves be "focused"?

  • Grinkle
  • · Replies 14 ·
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14

Undergrad How can we observe and measure interacting vacuum?

  • victorvmotti
  • · Replies 1 ·
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1

Undergrad How should we interpret the Möbius-strip image of spinors?

  • pellis
  • · Replies 1 ·
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1

Undergrad Why ##S_z|+\rangle=\frac{\hbar}{2}|+\rangle##

  • Kashmir
  • · Replies 8 ·
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8

Undergrad Frequency of EM waves in classical and quantum physics

  • donniedarko
  • · Replies 26 ·
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26

High School What proof do we have of wave functions?

  • Physics Slayer
  • · Replies 16 ·
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16

Undergrad Bell vs Kolmogorov: Unravelling Probability Theory Limits

  • Killtech
  • · Replies 93 ·
4
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93

Graduate Call for experiment : Delayed Choice and Quantum Zeno Effect

  • hyksos
  • · Replies 18 ·
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18

High School Unitarity in GR+QFT: Obeying Full QG Model?

  • Question69
  • · Replies 2 ·
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2

High School Wave-Particle Duality -- When is it a wave and when is it a particle?

  • alexandrinushka
  • · Replies 27 ·
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27

Undergrad What is the difference between charge and force carriers?

  • JohnH
  • · Replies 3 ·
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3

Undergrad X-ray fluorescence photons question

  • GTrax
  • · Replies 5 ·
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5

Graduate Measurement in QFT: Mapping Fields to Theory's Math Formalism

  • Jdeloz828
  • · Replies 31 ·
2
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31

High School Quantum Entanglement information transmission idea to knock down....

  • LozD
  • · Replies 41 ·
2
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41