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 happens to the eigenvalue if an operator acts on a bra?

  • shedrick94
  • · Replies 7 ·
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7

Undergrad How to find the spin number of a molecule like water

  • TheCanadian
  • · Replies 3 ·
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3

High School What counts as observer effect?

  • Gaz
  • · Replies 24 ·
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24

Undergrad Expanding the Fermi-Dirac integral by Taylor series

  • arneet
  • · Replies 3 ·
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3

Undergrad What is the spin quantum number of an atom in 4P state?

  • shedrick94
  • · Replies 7 ·
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7

Undergrad Macroscopic wavefunction evolution

  • durant35
  • · Replies 9 ·
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9

Graduate Hawking multiverse implications for "all" histories

  • trinko
  • · Replies 3 ·
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3

Undergrad Quantum Key Distribution - interception confusion

  • JaneHall89
  • · Replies 1 ·
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1

Undergrad Measuring entangled state of degenerate eigenstates

  • maxverywell
  • · Replies 4 ·
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4

Undergrad Energy of a number of particles

  • EmilyRuck
  • · Replies 15 ·
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15

Undergrad How do Z-Dir and N-Dir Spins Affect Entangled State Measurements?

  • JaneHall89
  • · Replies 7 ·
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7

Undergrad Degeneracy in quantum statistics

  • arneet
  • · Replies 4 ·
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4

High School What groundbreaking insights can quantum physics research on the ISS reveal?

  • 1oldman2
  • · Replies 3 ·
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3

Undergrad Singlet and triplet spin states - the normalisation constant

  • Sara Kennedy
  • · Replies 15 ·
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15

Undergrad What is the meaning of phase in relation to laser states?

  • kaje
  • · Replies 1 ·
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1

Undergrad Non-Newtonian fluids at the quantum level

  • thebosonbreaker
  • · Replies 2 ·
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2

Graduate Best first book on quantum mechanics

  • almarpa
  • · Replies 22 ·
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22

Undergrad Can an electron in an s-orbital exist at the nucleus (r=0)?

  • Steven Hanna
  • · Replies 2 ·
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2

High School Begining of time, cause and effect and quantum randomness

  • tim1608
  • · Replies 6 ·
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6

High School What does bosonization mean for electronics and quantum computers?

  • wolram
  • · Replies 1 ·
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1

High School What is stopping potential and what does the formula e × Vs mean?

  • Gajan1234
  • · Replies 5 ·
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5

Undergrad Examples of Basic Potential functions

  • DaTario
  • · Replies 3 ·
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3

Undergrad How Does Quantum Mechanics Relate to Quantum Field Theory in Particle Physics?

  • fxdung
  • · Replies 267 ·
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Undergrad Simulation Hypothesis and Skynet

  • Curiousphy
  • · Replies 2 ·
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2

High School Number of entangled particles in nature

  • entropy1
  • · Replies 16 ·
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16

Undergrad Schrodinger equation and stationary states

  • amjad-sh
  • · Replies 12 ·
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12

Graduate Canonical quantization of scalar fields

  • Higgsy
  • · Replies 3 ·
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3

High School Can entanglement be broken easily

  • KarminValso1724
  • · Replies 1 ·
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1

Undergrad Derivation of the photon energy

  • shaiyefet
  • · Replies 4 ·
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4

High School What is Quantum Statistical Mechanics?

  • fxdung
  • · Replies 33 ·
2
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Undergrad Why are the gamma-matrices invariant?

  • PatrickUrania
  • · Replies 71 ·
3
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High School So the holographic principle doesn't have much evidence?

  • Chrisjohnson
  • · Replies 20 ·
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20

Undergrad Why is there only odd eigenfunctions for a 1/2 harmonic oscillator

  • thegirl
  • · Replies 2 ·
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2

High School Interference patterns of electrons vs. photons

  • entropy1
  • · Replies 4 ·
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4

High School Electrons and ions -- how long can they exist apart?

  • Gajan1234
  • · Replies 2 ·
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2

Undergrad Why can't macroscopic objects maintain quantum coherence like superconductors?

  • durant35
  • · Replies 10 ·
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10

High School Does quantum mechanics explain why subatomic particles behave the way they do?

  • KarminValso1724
  • · Replies 3 ·
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3

High School Why do the 4 forces have the strength that they do?

  • KarminValso1724
  • · Replies 3 ·
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3

Undergrad Why must the graviton be spin-2 and how does it differ from other bosons?

  • bbbl67
  • · Replies 31 ·
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Undergrad Why electron enters the lowest potential possible?

  • Tahmeed
  • · Replies 1 ·
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1

Undergrad Sign convention in X-axis rotation Hamiltonian and unitary

  • Strilanc
  • · Replies 3 ·
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3

Graduate Can the Markov chain be used in qubit manipulation?

  • Cristina Maria
  • · Replies 2 ·
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2

Undergrad Energy quantization of the particle in a box

  • bodyscripter
  • · Replies 3 ·
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3

Graduate Optical Bistability and the Jaynes-Cummings Model

  • Raptor112
  • · Replies 11 ·
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11

Undergrad A special relativity explanation for the Lorentz Force?

  • tim9000
  • · Replies 10 ·
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10

Graduate Liouville Master Equation for an Open Quantum System

  • Raptor112
  • · Replies 10 ·
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10

Undergrad Probability density and kinetic

  • Incand
  • · Replies 3 ·
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3

Undergrad Does the probability collapse theory of QM imply backward in time

  • fredt17
  • · Replies 12 ·
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12

Undergrad When do excited states need multiple Slater determinants?

  • HAYAO
  • · Replies 13 ·
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13

High School How Do Virtual Photons Mediate Forces in Quantum Electrodynamics?

  • KarminValso1724
  • · Replies 1 ·
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1

Undergrad Why can spin-x eigenstates be written as superpositions of spin-z eigenstates?

  • Sara Kennedy
  • · Replies 4 ·
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4

Undergrad Can interactions happen at less than the Planck Time?

  • bbbl67
  • · Replies 3 ·
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3

Undergrad Normalizing Constant 3D Infinite Well

  • RaulTheUCSCSlug
  • · Replies 5 ·
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5

Undergrad Virtual particles in Feynman diagrams and not

  • friend
  • · Replies 11 ·
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11

Undergrad Expression for Uncertainty of Arbitrary Operator

  • DrPapper
  • · Replies 3 ·
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3

Undergrad Why is there a -1/2 in the Lagrangian density for ω mesons?

  • izzi wekwek
  • · Replies 2 ·
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2

High School Do probabilities for entangled polarization states add up to one?

  • klw289
  • · Replies 4 ·
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4

Undergrad Postulates for the formal core of quantum mechanics

  • A. Neumaier
  • · Replies 8 ·
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8

Graduate Fermi energy Ef changes with applied electric field?

  • Dimani4
  • · Replies 5 ·
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5

Graduate What is a "quantum potential" ?

  • momo666
  • · Replies 4 ·
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4

Undergrad Wave-particle duality and localization

  • amjad-sh
  • · Replies 8 ·
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8

High School Faster than light communication via entanglement?

  • Chrisjohnson
  • · Replies 19 ·
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19

Undergrad Difference between expectation value and eigenvalue

  • Sara Kennedy
  • · Replies 5 ·
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5

Undergrad What are the deep theoretical reasons for electron spin?

  • BiGyElLoWhAt
  • · Replies 19 ·
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19

High School The sticky elactic in the Bloch sphere

  • naima
  • · Replies 1 ·
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1

Undergrad What Is the Descriptive Meaning of \(- \frac{e}{c}\vec A\)?

  • Anton Alice
  • · Replies 3 ·
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3

Undergrad How do total spin and magnetic quantum numbers combine for two identical 1/2 particles?

  • Sara Kennedy
  • · Replies 5 ·
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5

Graduate Quantum Optics Question and Wigner Functions

  • Raptor112
  • · Replies 1 ·
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1

Graduate Is Phase Relevant for Uncharged Particles?

  • LarryS
  • · Replies 1 ·
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1

Undergrad Deciphering equations from Dirac's YouTube lecture videos

  • kq6up
  • · Replies 2 ·
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2

Undergrad Why do bosons have integer spin and fermions have half-integer spin?

  • bbbl67
  • · Replies 5 ·
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5

Undergrad How to prove Schrodinger's equation in momentum space?

  • Joker93
  • · Replies 8 ·
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8

High School Do Photons Contribute to the Energy Released in Nuclear Explosions?

  • thetexan
  • · Replies 2 ·
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2

Graduate Euclidean signature and compact gauge group

  • Einj
  • · Replies 5 ·
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5

Undergrad General Solution of Dirac Delta Potential Well

  • rbwang1225
  • · Replies 4 ·
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4

High School Does Photon Emission Cause Decoherence?

  • Feeble Wonk
  • · Replies 43 ·
2
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43

Undergrad Why is reflection coefficient |B|²/|A|² for scattering from delta function potential?

  • Danny Boy
  • · Replies 20 ·
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20

High School What takes up the empty space of an atom?

  • Chrisjohnson
  • · Replies 11 ·
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11

Graduate Time correlation of an observable in the Schrödinger picture

  • kith
  • · Replies 6 ·
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6

Graduate Why use adiabatic evolution instead of cooling?

  • mupsi
  • · Replies 6 ·
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6

High School When are particles in a quantum state?

  • Fiziqs
  • · Replies 20 ·
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20

Graduate What's meant by D dimensional gas?

  • erbilsilik
  • · Replies 1 ·
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1

Undergrad Do entangled particles exist in superposition?

  • friend
  • · Replies 14 ·
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14

Graduate Steane Code, Distance 3-Stabilizer-Codes

  • mupsi
  • · Replies 8 ·
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8

Undergrad How Do Photons Behave When They Intersect?

  • Passionate Eng
  • · Replies 1 ·
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1

Undergrad Teleportation isn't exclusively quantum....?

  • DirkMan
  • · Replies 2 ·
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2

Undergrad The barrier length in quantum tunneling

  • Alan Ezra
  • · Replies 5 ·
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5

Graduate Water molecule first hyperpolarizability

  • Konte
  • · Replies 3 ·
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3

Graduate Dispersive Regime in Jaynes-Cummings Model

  • Raptor112
  • · Replies 2 ·
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2

Undergrad Thermal radiation and light pump

  • Matej Kurtulik
  • · Replies 2 ·
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2

Undergrad Software Designs Quantum Experiments

  • Hornbein
  • · Replies 3 ·
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3

Undergrad How can I write a normalized spin superposition in a simplified form?

  • Ananthan9470
  • · Replies 2 ·
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2

Undergrad Weinberg Lectures on QM (2013 ed.), Equation 6.5.5

  • jouvelot
  • · Replies 2 ·
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2

Graduate What is the relationship between the Casimir force and the strong nuclear force?

  • nebulacollector
  • · Replies 10 ·
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10

High School Is Solving Schrodinger's Equation the Best Way to Approach Quantum Mechanics?

  • houlahound
  • · Replies 17 ·
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17

Undergrad Transmission coefficient limit

  • TheCanadian
  • · Replies 1 ·
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1

Undergrad What are magnetic and electric fields?

  • John_RB
  • · Replies 7 ·
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7

Undergrad Can an Electron Absorb a Photon if the Next Energy Level is Full?

  • magicman54494
  • · Replies 1 ·
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1

Undergrad Quantum field and mediating particles

  • alivedude
  • · Replies 2 ·
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2

Graduate Tracks in particle detectors and quantum paths

  • TrickyDicky
  • · Replies 127 ·
5
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