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.
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Undergrad Why are Planck units considered fundamental?
- Conn_coord
- · Replies 23 ·
Undergrad Double-slit experiment with momentum entangled pair of photons
- Christian Thom
- · Replies 7 ·
Undergrad Speed of individual photons in a vacuum?
- LarryS
- · Replies 71 ·
Undergrad Measurement accuracy or variation
- Conn_coord
- · Replies 1 ·
Undergrad How does a process of a Raman transition break quantum entanglement?
- tade
- · Replies 6 ·
Undergrad What is this notation D|(n;n')|, and how to solve it?
- K-Manu
- · Replies 3 ·
Undergrad Spin expectation value for one particle vs actual measurement
- Ahmed1029
- · Replies 4 ·
High School How is energy transferred from a wave to a photon?
- curiouschris
- · Replies 18 ·
Undergrad About photon-polariser interaction quantum-molecular-level mechanics
- tade
- · Replies 2 ·
Undergrad Curious about an idea of a modified polariser to send signals with QE
- tade
- · Replies 99 ·
Undergrad Weinberg Lectures in QM (2013 Ed.), Equation 7.10.15
- jouvelot
- · Replies 8 ·
Undergrad Quantum mechanics stationary state
- happyparticle
- · Replies 2 ·
Undergrad Negative energy when a laser goes through lithium niobate crystal?
- gggnano
- · Replies 13 ·
Undergrad Density Operators of Pure States
- Dario56
- · Replies 21 ·
Undergrad Time-energy uncertainty relation
- dyn
- · Replies 33 ·
Undergrad Can I find a particle in two states simultaneously?
- Ahmed1029
- · Replies 2 ·
Undergrad Analytical proof of LASER production
- SteveHowe73
- · Replies 3 ·
Undergrad New Nobel Aspect contradicts himself on action at a distance bel
- RayTomes
- · Replies 2 ·
Undergrad Predetermination in quantum theory and information theory
- Green dwarf
- · Replies 15 ·
Undergrad In Bell's Theorem, communication
- ndvcxk123
- · Replies 1 ·
High School Will Quantum Entanglement Lead to a 2022 Nobel Prize in Physics?
- Duplex
- · Replies 2 ·
Graduate Many-Particle Wavefunction Question
- CuriousLearner8
- · Replies 13 ·
Undergrad Energy from quantum systems in an expanding universe?
- Suekdccia
- · Replies 1 ·
Graduate Concept of wavefunction and particle within Quantum Field Theory
- Jufa
- · Replies 7 ·
Undergrad Postive rays in cathode ray tube experiments?
- sol47739
- · Replies 2 ·
Graduate Why is the Clebsch-Gordan coefficient zero for l+1 with m₁=0, m₂=0?
- euphoricrhino
- · Replies 7 ·
Undergrad Wave packet experimental detection
- VVS2000
- · Replies 4 ·
Graduate Does there exist a proof for these conjectures?
- hilbert2
- · Replies 2 ·
High School What’s the necessity of the strong force?
- Th3
- · Replies 2 ·
Undergrad About normalization of periodic wave function
- KFC
- · Replies 4 ·
High School Is there another workable interpretation of the Bell Inequality?
- .Scott
- · Replies 4 ·
Undergrad How can gravitons have anti particles?
- BadgerBadger92
- · Replies 24 ·
Undergrad Why does the QFT Lagrangian not already use operators?
- Gerenuk
- · Replies 11 ·
Undergrad Is Planck's Law of Black-Body Accurate?
- happyparticle
- · Replies 7 ·
Undergrad What sense does it make to "weigh" a Casimir cavity?
- timmdeeg
- · Replies 9 ·
Undergrad Einstein summation convention in QM
- dyn
- · Replies 19 ·
Undergrad Has the Unruh Effect ever been observed?
- lindberg
- · Replies 13 ·
Undergrad Quantum events near a black hole
- gnnmartin
- · Replies 25 ·
Undergrad How Do Radio Antennas Function in Quantum Mechanics?
- sol47739
- · Replies 4 ·
Undergrad Time-dependent to time-independent Schrödinger equation
- LagrangeEuler
- · Replies 5 ·
Graduate What is a "transient" value in the Ising model?
- user366312
- · Replies 1 ·
High School About infinity and all possibilities of Multiverse/Omniverse
- Ug Nagdi
- · Replies 14 ·
Undergrad Haag's Theorem: Explain Free Field Nature
- lindberg
- · Replies 4 ·
Undergrad Learning Planck's constant from the photoelectric effect experiment
- Hakimderubeis
- · Replies 4 ·
Matrices Often Used in Quantum Computing
- Ackbach
- · Replies 3 ·
Undergrad The CMB has a thermal black body spectrum
- Conn_coord
- · Replies 18 ·
Undergrad Polarization of photons quantum mechanically
- sol47739
- · Replies 3 ·
High School Understanding Waves, Particles and Probabilities
- geordief
- · Replies 2 ·
Undergrad Does chaos amplify inherent quantum level randomness?
- Physicist248
- · Replies 39 ·
Undergrad Detecting the sign change when a spinor rotates through 360 degrees
- wnvl2
- · Replies 1 ·
Undergrad Operators in finite dimension Hilbert space
- Sebas4
- · Replies 7 ·
Graduate What are the basic mathematical objects in QFT?
- snoopies622
- · Replies 7 ·
Undergrad How does one compute the Fourier-Transform of the Dirac-Hamiltonian?
- PhysicsRock
- · Replies 6 ·
Different Kinds of Quantum Computing Measurement Operators
- Ackbach
- · Replies 2 ·
Undergrad Understanding No Energy Degeneracy in Sakurai's Quantum Mechanics
- euphoricrhino
- · Replies 2 ·
Graduate Requirements for EIT with pulsed laser
- wangvivi
- · Replies 1 ·
Undergrad Where does the QM creation operator get its energy?
- joneall
- · Replies 29 ·
Undergrad Inner product - positive or positive semidefinite?
- dyn
- · Replies 21 ·
Undergrad The Wavefunction when Mass is Much Greater than Planck's Constant
- JohnH
- · Replies 21 ·
Undergrad Wondering why quantum entanglement occurs
- ebmg123
- · Replies 2 ·
Quantum Computing: Positive Operators are Hermitian
- Ackbach
- · Replies 2 ·
Undergrad Why is the SE better than the KG equation for a hydrogen atom?
- snoopies622
- · Replies 18 ·
High School Heisenberg's Uncertainty Principle and determinism
- riballoon
- · Replies 13 ·
High School Sinusoidal wave function of t and x
- Ennio
- · Replies 2 ·
Undergrad Vector operator acting on a ket gives a ket out of the state space
- Kashmir
- · Replies 11 ·
High School Positive Definite Cartan Matrices in Quantum Physics
- fresh_42
- · Replies 6 ·
Undergrad Can split photons have different spin probability than unsplit photons?
- ndvcxk123
- · Replies 2 ·
Undergrad What is so compelling in the superposition theorem?
- jinto26
- · Replies 3 ·
Undergrad Inner and Outer Product of the Wavefunctions
- Dario56
- · Replies 8 ·
Undergrad Understanding Wave Function Probabilities for a Free Particle
- jjson775
- · Replies 25 ·
Undergrad Entanglement and FTL signaling in professional scientific literature
- Delta2
- · Replies 276 ·
Undergrad How does atomic absorption spectroscopy work
- Login
- · Replies 1 ·
High School The relationship between the particle, the wave and the field
- geordief
- · Replies 8 ·
Graduate Coherent quantization, the non-unitary case
- mitchell porter
- · Replies 5 ·
High School Can quantum probabilities ever be exactly zero?
- CosmicVoyager
- · Replies 4 ·
Graduate Matrix representation of a unitary operator, change of basis
- Kashmir
- · Replies 1 ·
High School Is the quantum concept of a photon still poorly understood?
- CPW
- · Replies 32 ·
Graduate Is there a lost information paradox for quantum physics?
- Heidi
- · Replies 16 ·
Graduate Why does stimulated Raman emission require strong phonon damping?
- ure227922
- · Replies 2 ·
High School How does exchange of elementary particles result in a force?
- vcsharp2003
- · Replies 13 ·
Undergrad Questions about Franck-Condon principle
- Salmone
- · Replies 3 ·
Undergrad When and why does an electron emit a photon?
- Daniel Hendriks
- · Replies 15 ·
Graduate Probability flux integrated over all space is mean momentum?
- euphoricrhino
- · Replies 2 ·
Undergrad Trying to Understand the 1928 article by Raman on Nature
- Salmone
- · Replies 3 ·
Undergrad Understanding Spin States in 2D Vector Spaces
- robphippen
- · Replies 6 ·
Undergrad Potential energy at maximum amplitude in Morse potential ground state
- Salmone
- · Replies 2 ·
Undergrad With chips having 2 nm transistors, are we at the end of Moore's Law?
- swampwiz
- · Replies 2 ·
Undergrad Counterfactual quantum computation on interferometer
- artis
- · Replies 1 ·
High School What is a non-local Hamiltonian?
- lindberg
- · Replies 20 ·
Undergrad Determining the Number of Points in the n-Space
- Dario56
- · Replies 16 ·
Graduate Can local conservation be verified experimentally?
- Demystifier
- · Replies 12 ·
Undergrad Has Google Truly Achieved Quantum Supremacy?
- bhobba
- · Replies 9 ·
Undergrad Definition of functional derivative
- PreposterousUniverse
- · Replies 4 ·
Graduate Quantum Properties of Quasi Static Electric Fields
- Javelin
- · Replies 1 ·
High School What sort of an experiment can refute QM or QFTs?
- MathematicalPhysicist
- · Replies 124 ·
Undergrad Is the Energy Expectation Value Always Real and Above a Minimum Potential?
- dyn
- · Replies 14 ·
High School Is the concept of "potential" just a mathematical model?
- zb23
- · Replies 21 ·
Undergrad Quantum computation and entropy
- antonantal
- · Replies 39 ·
High School Questions about the position of the particle
- SLSPS
- · Replies 6 ·
High School Why do subatomic particles change what they do when observed?
- curiosity1
- · Replies 3 ·