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 Interaction picture (Is there a mistake in QFT books?)

  • jdstokes
  • · Replies 3 ·
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Graduate State of an electron, including spin

  • msumm21
  • · Replies 2 ·
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2

Graduate Heuristic explanation of why quantum mechanics plus SR imply antiparticles

  • feynmann
  • · Replies 4 ·
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4

Graduate Sudden Approximation and Adiabatic theorem

  • Yiping
  • · Replies 1 ·
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1

Graduate Treating operators with continuous spectra as if they had actual eigenvectors?

  • Marcaias
  • · Replies 1 ·
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Graduate IV curve on photoelectric effect

  • KFC
  • · Replies 1 ·
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Graduate Phonons vs Gauge Bosons: What's the Difference?

  • nuby
  • · Replies 1 ·
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Graduate Is There a Link Between the Brain and Dark Energy?

  • PJ2001
  • · Replies 1 ·
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1

Graduate Solving Potential V with Schrodinger Equation

  • KFC
  • · Replies 5 ·
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5

Undergrad Fundamental reason behind Aufbau principle

  • tgt
  • · Replies 3 ·
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3

Graduate Adiabatic Spin Manipulation in EPR Experiment

  • Jon_Trevathan
  • · Replies 8 ·
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8

Undergrad Looking for Layman's Physical Explanation for the lowest energy level in atoms

  • feynmann
  • · Replies 29 ·
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Graduate When a particle tunnels where does the energy come from

  • matt_crouch
  • · Replies 9 ·
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9

Graduate Photons determine the property of an electromagnetic wave

  • FrankJ777
  • · Replies 5 ·
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Graduate Quantum Fluctuations of Negative Energy

  • Unredeemed
  • · Replies 7 ·
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7

Graduate What is the Lamb-Dicke regime and how does it impact ion trapping experiments?

  • Nusc
  • · Replies 2 ·
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Graduate Can spin-1/2 particles interfere after a Stern-Gerlach device?

  • msumm21
  • · Replies 12 ·
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12

Graduate Raising and lowering operators acting on spin 1 kets?

  • philip041
  • · Replies 3 ·
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3

Graduate Quantized vs. Continuous Variables

  • Tac-Tics
  • · Replies 11 ·
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11

Graduate Why Is the Uncertainty Principle Considered Strange?

  • mskaroly
  • · Replies 3 ·
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3

Undergrad Recommended references for quantum vs classical physics

  • noobie!
  • · Replies 2 ·
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Graduate The Hilbert space of non-relativistic QM

  • Fredrik
  • · Replies 5 ·
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5

Graduate About momentum operator in other coordinate system

  • KFC
  • · Replies 1 ·
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1

Graduate Is wave-particle duality paradoxical at the foundation of quantum mechanics?

  • tgt
  • · Replies 38 ·
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Graduate Direct Position Measurement on a Microscopic Scale with Twin Photons

  • newbee
  • · Replies 48 ·
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Graduate Why do spin ½ particles need two full rotations to return to their original state?

  • Love*Physics
  • · Replies 15 ·
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15

Graduate Identical bosons vs. fermions in square potential well

  • bobshae
  • · Replies 2 ·
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Graduate Gauge Invariance: Classical vs Quantum

  • captain
  • · Replies 4 ·
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4

Graduate Pauli's Wave Mechanics text. h vs. hbar

  • Peeter
  • · Replies 2 ·
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2

Graduate Does the uncertainty principle affect gravitational fields?

  • spidey
  • · Replies 19 ·
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19

Graduate What is Quantum Theory and Why Do Electrons Orbit at Specific Distances?

  • quantum brain
  • · Replies 5 ·
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Graduate Product State Bra Order: Correct Form?

  • KFC
  • · Replies 2 ·
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2

Graduate Why does reflection conserve coherence if photons transfer momentum?

  • Dmitry67
  • · Replies 2 ·
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2

Undergrad Why do we use short wavelength photons in Compton scattering?

  • KFC
  • · Replies 2 ·
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2

Graduate Does the calculated large cosmological constant in falsify QFT?

  • ensabah6
  • · Replies 6 ·
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6

Graduate Quantization and fluid mechanics?

  • quantumfireball
  • · Replies 7 ·
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7

Graduate Evaluating Feynman diagram in QFT without external fermion lines

  • Amanheis
  • · Replies 4 ·
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4

Graduate Energy partition between molecules and radiation in a laser cavity at equilibrium

  • Phrak
  • · Replies 11 ·
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11

Graduate Raising and lowering operators on a ket?

  • philip041
  • · Replies 18 ·
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18

Graduate Orders of magnutide in Heisenberg's uncertainty principle

  • Heirot
  • · Replies 3 ·
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Graduate The intense laser-atom physics and ionized electron

  • xylai
  • · Replies 7 ·
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7

Graduate Does an operator on a bra state require taking its adjoint?

  • KFC
  • · Replies 9 ·
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9

Graduate How does destructive interference set in when action exceeds h-bar in path integrals?

  • sumeetkd
  • · Replies 1 ·
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Graduate Why can't we determine both energy and time exactly?

  • pi.rootpi
  • · Replies 3 ·
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Graduate Understanding Spin States in Quantum Mechanics

  • KFC
  • · Replies 2 ·
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2

Undergrad Basics of Quantum Chemistry, especially entanglement

  • darkmatter(s)
  • · Replies 5 ·
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Graduate Is a Photon Massless or Does it Have Relativistic Mass?

  • Nphysicist
  • · Replies 13 ·
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Graduate Operating on spin angular momenta

  • runninglow
  • · Replies 1 ·
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Graduate Pulsing a diode laser with very long pulses and very low repetition rates

  • r_daniel
  • · Replies 2 ·
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Graduate Two Identical Particles w/ Spin State s

  • degerativpart
  • · Replies 3 ·
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Graduate Born rule vs ABL rule and time reversal in quantum mechanics

  • Fredrik
  • · Replies 15 ·
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Graduate Greatest accuracy in the |mn> state is |n| = m

  • bra-kets
  • · Replies 2 ·
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Graduate What are conjugate variables and why is there an uncertainty relation between them?

  • spidey
  • · Replies 2 ·
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Graduate Properties of the Dirac delta function

  • Fredrik
  • · Replies 1 ·
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Graduate Casimir Effect and Perpetual Motion

  • Zeteg
  • · Replies 16 ·
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16

Graduate Expectation value for radius of an electron in a hydrogen atom

  • emperrotta
  • · Replies 8 ·
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Graduate Older formulation of Pauli exclusion principle

  • kandhakumar
  • · Replies 2 ·
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Graduate Drawback of Hartree Product in Chemistry

  • kandhakumar
  • · Replies 2 ·
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Graduate Communicating through wave function collapse

  • McGarr
  • · Replies 10 ·
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10

Graduate Cavitation-does it relate to the Big Bang?

  • Earnest Stuar
  • · Replies 6 ·
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6

High School Looking for Layman's Physical Explanation for energy level in atoms

  • feynmann
  • · Replies 23 ·
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23

Graduate Does an electron have a makeup

  • ryn17
  • · Replies 72 ·
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Graduate Commutate relation of lowering operator and sperical tensor operators

  • Einsling
  • · Replies 1 ·
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1

Graduate What are the key misconceptions about quantum mechanics interpretations?

  • thenewmans
  • · Replies 1 ·
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1

Graduate Why does the wave function depend on time in a stationary state?

  • KFC
  • · Replies 5 ·
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5

Graduate Are atoms spherical, or is that just a visualization model?

  • Chaos' lil bro Order
  • · Replies 30 ·
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Graduate Effects of the Variation of the Parameters of the Standard Model

  • Dmitry67
  • · Replies 2 ·
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2

Graduate What Is the Ground State of Bound Fermions in a Box?

  • Evgeny Naumov
  • · Replies 11 ·
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Graduate Quantum Field Theory: Multiparticles and Single Particles

  • martyf
  • · Replies 2 ·
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2

Graduate Need a topic for paper in modern physics

  • dswatson
  • · Replies 7 ·
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7

Graduate Quantum Decoherence - how fast does it propagate?

  • Dmitry67
  • · Replies 15 ·
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15

Graduate Peskin - exponention of disconnected diagrams

  • PJK
  • · Replies 3 ·
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3

Graduate If we know a photon's momentum, can it be anywhere in the universe?

  • glueball8
  • · Replies 1 ·
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1

Graduate Why quantization resolves negative energy in Klein-Gordon equation

  • martyf
  • · Replies 1 ·
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1

Graduate Quantum observation and gravity as combined probability distributions

  • lkubat
  • · Replies 13 ·
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13

Graduate Does backwards time travel violate the Heisenberg uncertainty principle?

  • Math Jeans
  • · Replies 31 ·
2
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31

Graduate Interference pattern given many which-path detectors?

  • gendou2
  • · Replies 2 ·
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2

Graduate Absorption Paradox: Continuous Photon Energies and Quantized Molecule Energies

  • p.tryon
  • · Replies 5 ·
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5

Undergrad Photon spin - experimental evidence

  • Usaf Moji
  • · Replies 6 ·
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6

Graduate Is Everything in the Universe Entangled According to Physics?

  • pallidin
  • · Replies 77 ·
3
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Graduate Do spontaneous and stimulated emission obey to a Boltzmann's statistics ?

  • fred_run
  • · Replies 6 ·
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6

Undergrad Can photons be generated without electrical current?

  • cam875
  • · Replies 34 ·
2
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34

Graduate How Does Aperture Size Affect Laser Beam Uncertainty?

  • fisico30
  • · Replies 4 ·
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4

Graduate WE theorem to evaluate matrix elements

  • pollo
  • · Replies 1 ·
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1

Graduate The physical meaning of Pauli Spin Matrices

  • gn0m0n
  • · Replies 16 ·
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16

Graduate Size does matter? Rayleigh scattering question

  • DeepSeeded
  • · Replies 1 ·
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1

Graduate What does the |jjjj⟩ state represent in hydrogen atom wavefunctions?

  • mrjammin
  • · Replies 1 ·
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1

Graduate Conservation of momentum in QFT

  • jdstokes
  • · Replies 1 ·
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1

Graduate Vastness of space and infinite universes

  • bxadook
  • · Replies 3 ·
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3

Undergrad Problem in the Defination of electon's wavelength

  • soopo
  • · Replies 2 ·
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2

Undergrad Can Events with Zero Probability Actually Occur?

  • lax1113
  • · Replies 23 ·
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23

Undergrad No coupling of Photons with eletric fields

  • eintagsfliege
  • · Replies 3 ·
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3

Graduate Quantum Eraser and Delayed Choice Quantum Eraser

  • thenewmans
  • · Replies 1 ·
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1

Graduate What exactly is psi(x) in quantum mechanics?

  • joker_900
  • · Replies 12 ·
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12

Graduate Prove Spinor Identity in Arbitrary Dimension

  • ismaili
  • · Replies 1 ·
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1

Graduate Does the Delayed Choice Experiment Challenge Classical Intuition?

  • debra
  • · Replies 1 ·
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1

Graduate Is Angular Momentum Quantized in a Free Electron's Non-Orbital Motion?

  • Eezekiel
  • · Replies 14 ·
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14

Graduate Wouldn't the Geiger Counter be considered a measuring device in SC?

  • esvion
  • · Replies 1 ·
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1

Undergrad Refraction - The lingering question

  • Burningmace
  • · Replies 12 ·
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12

Graduate Why 1D well must has this solution?

  • KFC
  • · Replies 6 ·
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6