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 Vertex function, quantum action
- The black vegetable
- · Replies 2 ·
Undergrad Finding matrices of perturbation using creation/annihilation operators
- Keru
- · Replies 3 ·
High School Measuring entangled photons in different polarization bases
- StevieTNZ
- · Replies 3 ·
Graduate Bremsstrahlung single photon or spectrum
- gjj
- · Replies 1 ·
Undergrad Accuracy of the Density of States
- JohnnyGui
- · Replies 3 ·
Graduate Coherent states: Orthonormal set? Overcomplete basis?
- LagrangeEuler
- · Replies 1 ·
High School Ionization energy and energy levels
- ilovepudding
- · Replies 11 ·
Undergrad Group Theory Appearing in Griffith's Elementary Particles (2nd Ed.)
- Jdeloz828
- · Replies 20 ·
Graduate How ‘spooky’ is quantum physics? The answer could be incalculable
- Demystifier
- · Replies 24 ·
Undergrad Why perturbation theory uses power series?
- Phylosopher
- · Replies 13 ·
Undergrad Splitting of a one-particle wave function
- Spacetime walker
- · Replies 15 ·
Graduate Why is the quantum Fisher information useful in quantum metrology?
- jamie.j1989
- · Replies 1 ·
High School What's the exact point about time travel?
- Benjamin_harsh
- · Replies 6 ·
Undergrad (Baby QM) Analytic Solution to the Infinite Square Well Problem
- obstinatus
- · Replies 2 ·
Graduate Decoupled spin vectors A and B
- filip97
- · Replies 1 ·
Graduate How are basis vector relationships defined in incompatible propositions?
- forkosh
- · Replies 1 ·
Undergrad Nomenclature : global or constant phase
- jk22
- · Replies 3 ·
Undergrad Fermi's golden rule derivation a bit hazy
- Replusz
- · Replies 4 ·
High School Quantum computing -- How is the relevant solution selected?
- jeremyfiennes
- · Replies 4 ·
Graduate Does Adding or Removing an Electron Change a Helium-3 Atom to a Boson?
- hilbert2
- · Replies 14 ·
Graduate Product of Representations of Lorentz Group
- filip97
- · Replies 1 ·
Graduate Superluminal origin of Quantum Mechanics
- andresB
- · Replies 4 ·
Undergrad Thought experiment on photon entanglement
- Steve Blandford
- · Replies 14 ·
Undergrad Vacuum amplitudes in \phi^4 theory
- Replusz
- · Replies 6 ·
Undergrad Why does a superposition of z-spin states give definite x-spin?
- Sparky_
- · Replies 32 ·
Undergrad Commutator with gradient operator (nabla)
- Replusz
- · Replies 4 ·
Graduate Algebraic form of Klein Gordon ##\phi^4## vacuum and ladder operators
- QFT1995
- · Replies 5 ·
Undergrad Creation/annihilation operators question
- Antarres
- · Replies 5 ·
Undergrad What are time crystals and what are they made of?
- Quark Effect
- · Replies 8 ·
Undergrad Quantum Mechanics Particle in a Box
- umttrb
- · Replies 11 ·
Graduate Looking Under the Hood of Feynman Diagrams
- Jdeloz828
- · Replies 7 ·
Graduate Potential step at a Barrier in Quantum mechanics
- LagrangeEuler
- · Replies 6 ·
High School Are all quantum fields coherent?
- Wave Packets
- · Replies 14 ·
Graduate Finding periodic potentials from Bloch wave functions
- hilbert2
- · Replies 10 ·
Undergrad Do electrons interact with virtual particles at every instant?
- asimov42
- · Replies 10 ·
Undergrad Is the Kronecker Delta Calculation in Peskin and Schroeder's Solution Correct?
- MathematicalPhysicist
- · Replies 6 ·
Undergrad Quantum Measurement under Heisenberg Picture?
- LarryS
- · Replies 8 ·
Graduate Ground state energy of cube-like potential wells
- hilbert2
- · Replies 3 ·
Undergrad Why are particles off-shell in external fields?
- asimov42
- · Replies 3 ·
Graduate Validity of Scalar Field Lagrangian with Linear and Quadratic Terms
- Gaussian97
- · Replies 4 ·
Graduate QFT topics for entanglement entropy
- shinobi20
- · Replies 3 ·
Undergrad Wilczek on virtual particle reality and summing Feynman diagrams
- asimov42
- · Replies 13 ·
Undergrad The Dirac Equation: Understanding Spinors and Approximations
- park
- · Replies 3 ·
Undergrad Perturbation lines for the 1s hydrogen electron
- georg gill
- · Replies 10 ·
Undergrad Time measurement in a double slit experiment with single photons
- Marcin
- · Replies 48 ·
High School From radio signal to corresponding photons
- somega
- · Replies 1 ·
Graduate How to build a qubit (theoretically)?
- WAAAGH
- · Replies 8 ·
Undergrad What is the Fourier conjugate of spin?
- redtree
- · Replies 9 ·
Graduate Understanding Superposition Physically and Mathematically
- jambaugh
- · Replies 2 ·
Undergrad Atoms in a harmonic oscillator and number states
- jamie.j1989
- · Replies 5 ·
Graduate Quantum entanglement and quantum foundation
- kay_bee_93
- · Replies 1 ·
High School Questions about measurement devices in the double slit experiment
- UnderstandingQT
- · Replies 10 ·
Undergrad 2nd Order Perturbation Theory Energy Correction
- electrogeek
- · Replies 5 ·
Graduate Commutation between spin-operator and creation operator(QFT)
- retardedgreensfunc
- · Replies 4 ·
Graduate Quantum Information research frontier
- kay_bee_93
- · Replies 2 ·
Undergrad Definition of a Degenerate Subspace (QM)
- CGandC
- · Replies 12 ·
High School How does the double slit experimental apparatus actually work?
- leppad
- · Replies 7 ·
Graduate Double slit experiment with magnetic traps
- Marcin
- · Replies 33 ·
High School Adjoint Operation in Shankar's "Principles of Quantum Mechanics
- Getterdog
- · Replies 13 ·
Undergrad The density of states independent of Boundary Conditions
- dRic2
- · Replies 4 ·
Undergrad Valley degeneracy in tunneling current
- Noki Lee
- · Replies 1 ·
Graduate Effect of Spin on Vacuum Energy
- DrInfinity
- · Replies 25 ·
Undergrad Is there some agreement on properties of a theory of quantum gravity?
- KurtLudwig
- · Replies 2 ·
Undergrad What is an Eigenstate? Simple Explanation
- anni
- · Replies 5 ·
Undergrad When is <psi|AB|theta> equal to <psi|A|theta>*<psi|B|theta>?
- Getterdog
- · Replies 1 ·
Undergrad How Fourier transform and operator methods connect for conjugate variables
- nomadreid
- · Replies 7 ·
High School Why do double Hadamard gates cancel |1> but leave |0> and √2 unchanged?
- Quark Effect
- · Replies 2 ·
Undergrad Relationship between a Lie group such as So(3) and its Lie algebra
- MichaelAlexDavM
- · Replies 6 ·
High School What is the significance of 'i' in quantum computation notation?
- Quark Effect
- · Replies 7 ·
High School Is sunlight through gaps in leaves during an eclipse decohered?
- quantuminternet
- · Replies 4 ·
Undergrad When does the exchange operator commute with the Hamiltonian
- aliens123
- · Replies 13 ·
High School We can't unite QM with GR because of what the Qfield is capable of
- quantuminternet
- · Replies 3 ·
Undergrad Why doesn't an electron bounce in the direction of the incident light?
- cemtu
- · Replies 5 ·
High School How do orthogonal waves interfere?
- Kuribali
- · Replies 6 ·
Undergrad Understanding algorithmic information theory's reality
- sayetsu
- · Replies 2 ·
Graduate Commutation relations of N(k) with creation and annihilation operators in QFT
- JD_PM
- · Replies 10 ·
Graduate Stone's theorem on one-parameter unitary groups and new observables?
- victorvmotti
- · Replies 2 ·
Undergrad Rotation problem in Quantum Mechanics
- Adwit
- · Replies 10 ·
Undergrad Von Neumann entropy for "similar" pvm observables
- forkosh
- · Replies 2 ·
Undergrad Is the potential energy always negative in the ground state of a hydrogen atom?
- LagrangeEuler
- · Replies 12 ·
High School Emission from a coated cathode and tunneling
- Orthoceras
- · Replies 2 ·
Graduate What Conditions Allow the Derivative Trick for Evaluating Fermionic Commutators?
- thetafilippo
- · Replies 4 ·
Graduate How effective can QM be to understand the mind and/or consciousness?
- SEYED2001
- · Replies 13 ·
Undergrad Question on the SG (Stern-Gerlach) Spin experiment
- arkantos
- · Replies 8 ·
Graduate Learning coherent states beyond Griffiths
- Sunnyocean
- · Replies 11 ·
High School Can we measure any two of the energy, momentum or mass simultaneously?
- SEYED2001
- · Replies 10 ·
Graduate Understanding Hermiticity of Actions in QFT for Checking and Confirming
- John Greger
- · Replies 4 ·
Undergrad Imaginary Residuals in Solving the Schrodinger Equation
- Bob3141592
- · Replies 5 ·
Undergrad Can coherent states reveal classical orbits from quantum orbitals?
- arivero
- · Replies 12 ·
Graduate Lorentz transformation symmetry and angular momentum in QFT
- JD_PM
- · Replies 6 ·
Undergrad Why use antisymmetric tensor to flip Higgs doublet in up-quark coupling
- tomdodd4598
- · Replies 11 ·
Graduate Superficial Degree of Divergence in Renormalization of Phi^3 Theory
- The black vegetable
- · Replies 2 ·
Undergrad How to determine ##\psi(x,0)## in general situation?
- Kim hyeon su
- · Replies 1 ·
Undergrad Scalar Hamiltonian and electromagnetic transitions
- kelly0303
- · Replies 5 ·
Undergrad What does it mean to influence a quantum measurement's outcome?
- entropy1
- · Replies 23 ·
Undergrad Bell's theorem : pre- and post-digitization
- jk22
- · Replies 1 ·
High School What Are the Best References for Delayed Eraser Experiments with Electrons?
- jeremyfiennes
- · Replies 5 ·
High School How can electrons spin if they're waves of energy?
- Henrcr
- · Replies 11 ·
Undergrad Proof of Commutator Operator Identity
- Peter Yu
- · Replies 7 ·
Undergrad Planck's law in wavenumber vs. wavelength
- davidwinth
- · Replies 20 ·