Quantum basics Definition and 85 Threads

  1. Gary Venter

    I Quantum field in curved space-time

    The wave function includes coordinates for position in space. For two distant but correlated particles, do their distances and paths of movement used in the wave function follow the curved space-time of general relativity, or is Euclidean distance assumed in QM?
  2. L Drago

    B Heisenberg uncertainty principle -- Questions about a practical experiment

    Please review this experiment I watched from a video in YouTube and I think is correct. If there are flaws or there is a better experiment of proving this principle, kindly tell me.
  3. Frigorifico9

    I Is my interpretation of the g-factor correct?

    I'm trying to make sure I understand the g-factor of the electron, so if my question is flawed please don't just point out my flaws, but help me correct my understanding If I understand correctly the magnetic moment of an object depends on it charge, its mass and its momentum $$ \mu =...
  4. Frigorifico9

    I Who was the first to make a Stern-Gerlach experiment with two magnets?

    I'm trying to fill a conceptual gap I have in the history of physics In 1922 Stern and Gerlach make their experiment, proving that electrons have intrinsic angular momentum, however it takes a while for people to understand this. At first they think this is somehow caused by quantization of...
  5. golya

    I What Is Bell's Theorem and Why Does It Matter?

    Hi everyone, I need some help getting the gist of Bell’s theorem and his notion of inequalities. How would you explain it to someone with limited knowledge of mathematics? What are the potential implications?
  6. okaythanksbud

    B Extremely elementary questions about QM

    Im trying to learn QM on my own and I just want to clear some things up. I feel dumb writing some out but Id rather clear my confusion than believe im interpreting what I read correctly. From what I've read, every measurement of a system gives us values that are the eigenvalues of a certain...
  7. Y

    Quantum Theory, particle in a ring

    hello i would to get some help with my homework. 1. true 2. i dont know 3. true 4. i dont know 5, false 6. i dont know about 2,4,6 i really have know idea what to think I really appreciate help
  8. S

    What aspects of quantum theory are you curious about?

    As per my name, I am Quantum Newbie. I am I am exactly that. I'm interested more specifically in the following: mandella effect, butterfly effect, alternate universes, mirror worlds, bubble worlds, quantum mortality, crossovers, multiple paths on the same frequency, dementions, universe A and...
  9. James1238765

    I What is the significance of the T - V Lagrangian of a system?

    Let E be a fixed immutable quantity. E can be freely exchanged between T and V, as long as $$T + V = E$$ 1. What does the quantity $$\int_x T - V $$ signify? What is the importance of this quantity? -------------------- Let E now be the budget of a factory. E can either be spent on T or V in...
  10. lindberg

    B What is a non-local Hamiltonian?

    If I understand it correctly, the Hamiltonian represents the total energy of the system. Can it be non-local? If yes, doesn't this contradict relativistic locality?
  11. D

    Diagonalizing of Hamiltonian of electron and positron system

    What I did was first noting that ##\hat{\vec{S}}_1\cdot\hat{\vec{S}}_2=\frac{1}{2}(\hat{\vec{S}}^2-\hat{\vec{S}}_1^2-\hat{\vec{S}}_2^2)##, but these operators don't commute with ##\hat{S}_{1_z}## and ##\hat{S}_{2_z}##, this non the decoupled basis ##\ket{s_1,s_2;m_1,m_2}## nor the coupled one...
  12. C

    I Quantization of Quasiperiodic Orbits in the Bohr-Sommerfeld Model

    Recall that in the semi-classical Bohr-Sommerfeld quantization scheme from the early days of quantum mechanics, bound orbits were quantized according to the value of the action integral around a single loop of a closed path. Clearly this only makes sense if the orbits in question permit closed...
  13. Huzaifa

    Explain the Schrodinger equation

    Please explain in simple words, the meaning of the Schrodinger wave equation in the quantum mechanics model of atom. $$\frac{\partial^{2} \psi}{\partial x^{2}}+\frac{\partial^{2} \psi}{\partial y^{2}}+\frac{\partial^{2} \psi}{\partial z^{2}}+\frac{8 \pi^{2} m}{h^{2}}(E-U) \psi=0$$
  14. Z

    I Pauli spin matrices under inversion and 180 degree rotation?

    How do the Pauli spin matrices transform under an inversion ? I think I mean to say the 3 dimensional improper rotation which is just in 3 dimensional matrix notation minus the identity - so exactly how are the 2 dimensional Pauli spin matrices changed. And under a 180 rotation do the 'y' and...
  15. S

    A Definition of bi-local measurement by Masanes et al.

    Dear experts, I'm currently working my way through the paper Masanes, Galley, Müller, https://arxiv.org/abs/1811.11060. On page 3, they define what they call a bi-local measurement: If we have two systems a and b and we define an outcome probability function for some measurement f on system a...
  16. Q

    Is Quantum Entanglement the Key to Instantaneous Communication?

    Hey all! I'm Alexander, after all of the exposure quantum physics is getting in these Marvel movies I decided to study up and I must say Quantum Physics just doesn't set well with me. I'm very interested in what has been made capable due to the math involved with quantum physics. I have a large...
  17. Mutatis

    Find the normalization constant ##A##

    Homework Statement Find the noralization constant ##A## of the function bellow: $$ \psi(x) = A e^\left(i k x -x^2 \right) \left[ 1 + e^\left(-i \alpha \right) \right], $$ ##\alpha## is also a constant. Homework Equations ##\int_{-\infty}^{\infty} e^\left(-\lambda x^2 \right) \, dx = \sqrt...
  18. P

    I Why is the Phase Shift in Grover's Algorithm Applied to All Elements Except 0?

    Hi everybody, I've read some pages in Nielsens "Quantum Computing" book, it's very interesting, but especially at Grover's algorithm, there occurs a question for me. It is said that a phase shift is performed, which is defined as follows: ##|0\rangle \rightarrow |0\rangle \\ |x\rangle...
  19. L

    Help with finding the expectation value of x^2

    The question is as follows: A particle of mass m has the wave function psi(x, t) = A * e^( -a ( ( m*x^2 / hbar) +i*t ) ) where A and a are positive real constants. i don't know how to format my stuff on this website, so it may be a bit harder to read. Generally when i write "int" i mean the...
  20. D

    B The Nature of Measurement and Interaction in Quantum Mechanics

    I am still confused about the difference between measurement and interaction. I mean when electrons are traveling from source to the screen through the slits, there are air molecules in their way. And even if the electron double slit experiment is carried out in total vacuum in a completely...
  21. J

    B Is wave-particle duality a result of the relativity theory?

    Have thought about this for sometime but couldn't get deeper. I have speculated that wave-particle duality is a direct result of the relativity theory. Especially it could arise from the factor of length contraction (dimensionality reduction). So far, the particle reality is based on various...
  22. Safder Aree

    Harmonic Oscillator violating Heisenberg's Uncertainity

    Homework Statement Does the n = 2 state of a quantum harmonic oscillator violate the Heisenberg Uncertainty Principle? Homework Equations $$\sigma_x\sigma_p = \frac{\hbar}{2}$$ The Attempt at a Solution [/B] I worked out the solution for the second state of the harmonic oscillator...
  23. Mutatis

    Write the matrix representation of the raising operators....

    Homework Statement Hi, guys. The question is: For a 3-state system, |0⟩, |1⟩ and |2⟩, write the matrix representation of the raising operators ## \hat A, \hat A^\dagger ##, ## \hat x ## and ##\hat p ##. Homework Equations I know how to use all the above operators projecting them on...
  24. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 1: Black Body Radiation I

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 1: Black Body Radiation I

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  25. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 2: Black Body Radiation II

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 2: Black Body Radiation II

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  26. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 3: Black Body Radiation III

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 3: Black Body Radiation III

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  27. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 6: Black Body Radiation VI

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 6: Black Body Radiation VI

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  28. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 7: Black Body Radiation VII

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 7: Black Body Radiation VII

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  29. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 8: Radiation as a collection of particles called photons

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 8: Radiation as a collection of particles called photons

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  30. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 9: Quantum Hypothesis and specific heat of solids

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 9: Quantum Hypothesis and specific heat of solids

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  31. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 10: Bohr's Model of hydrogen spectrum

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 10: Bohr's Model of hydrogen spectrum

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  32. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 11: Wilson Sommerfeld quantum condition I

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 11: Wilson Sommerfeld quantum condition I

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  33. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 12: Wilson Sommerfeld quantum condition II

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 12: Wilson Sommerfeld quantum condition II

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  34. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 13: Wilson Sommerfeld quantum condition III

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 13: Wilson Sommerfeld quantum condition III

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  35. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 14: Quantum conditions and atomic structure

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 14: Quantum conditions and atomic structure

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  36. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 15: Eienstien's A and B coefficients

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 15: Eienstien's A and B coefficients

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  37. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 16: Stimulated emission and amplification of light in a LASER

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 16: Stimulated emission and amplification of light in a LASER

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  38. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 17: Brief description of a LASER

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 17: Brief description of a LASER

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  39. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 18: Introduction to the correspondence principle

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 18: Introduction to the correspondence principle

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  40. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 19: General nature of the correspondence principle

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 19: General nature of the correspondence principle

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  41. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 20: Selection rules (for transitions) through the correspondence principle

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 20: Selection rules (for transitions) through the correspondence principle

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  42. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 21: Applications of the correspondence principle

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 21: Applications of the correspondence principle

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  43. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 22: Heisenberg's formulations of quantum mechanics I

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 22: Heisenberg's formulations of quantum mechanics I

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  44. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 23: Heisenberg's formulations of quantum mechanics II

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 23: Heisenberg's formulations of quantum mechanics II

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  45. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 24: Heisenberg's formulations of quantum mechanics III

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 24: Heisenberg's formulations of quantum mechanics III

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  46. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 25: Brief introduction to matrix mechanics

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 25: Brief introduction to matrix mechanics

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  47. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 26: Introduction to waves and wave equation

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 26: Introduction to waves and wave equation

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  48. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 27: Sationary waves eigen values and eigen functions

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 27: Sationary waves eigen values and eigen functions

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  49. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 28: Matter waves and their experimental detection

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 28: Matter waves and their experimental detection

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
  50. Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 29: Representing a moving particle by a wave packet

    Introductory Quantum Mechanics with Prof. Manoj Harbola (NPTEL):- Lecture 29: Representing a moving particle by a wave packet

    All copyright reserved to Prof. Harbola and NPTEL, Govt. of India. Duplication punishable offence. Course Website: http://www.nptel.ac.in/courses/115104096/
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