Griffiths Quantum Mechanics Solutions
Complete video solutions to problems from "Introduction to Quantum Mechanics" by David J. Griffiths
About This Series
88 detailed video solutions covering problems from Griffiths' "Introduction to Quantum Mechanics" - the most widely used undergraduate quantum mechanics textbook. Each video provides step-by-step solutions with clear explanations of the physics and mathematics involved.
📘 Textbook Coverage
Problems from Chapters 1-11 of Griffiths QM
🎯 Step-by-Step
Detailed solutions with all mathematical steps shown
💡 Physical Insight
Understanding the physics behind each problem
Chapter 1: The Wave Function
Expectation Values (Gaussian)
For distribution: $\rho(x) = Ae^{-\lambda(x-a)^2}$
Video Lecture
Griffiths QM 1.6 Solution
Expectation values for Gaussian distribution
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Normalizing Piecewise Wavefunction
Video Lecture
Griffiths Problem 1.7
Normalizing a piecewise wavefunction
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Expectation Values (Exponential)
With absolute value: $|x|$
Video Lecture
Griffiths QM 1.8 Solution
Expectation values for exponential with absolute value
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Probability Current Derivation
Video Lecture
Griffiths QM 1.9
Derivation of the probability current
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Particle Lifetime (Complex Potential)
HARD PROBLEM
Video Lecture
Griffiths QM 1.10 Solution
Lifetime of a particle with complex potential
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Ehrenfest Theorem (Detailed Proof)
Video Lecture
Ehrenfest Theorem Proof
Detailed proof of Ehrenfest theorem
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Expectation Values (Gaussian Wavefunction)
HARD PROBLEM
Video Lecture
Griffiths QM 1.14 Solution
Expectation values for Gaussian wavefunction
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Chapter 2: Time-Independent Schrödinger Equation
Three Important Theorems
Video Lecture
Griffiths QM 2.1 (3rd ed) Solution
Proving three important theorems
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Energy Greater Than Potential
Proving $E > V_{\text{min}}$
Video Lecture
Griffiths QM Problem 2.2 Solution
Proving that energy has to be greater than potential
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Infinite Square Well Energy Bounds
Proving $E \neq 0$ and $E \not< 0$
Video Lecture
Problème 2.3 Griffiths QM
Infinite square well can't have E=0 or E<0
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Expectation Values & Uncertainty
Infinite square well uncertainty principle
Video Lecture
Griffiths QM Problem 2.5
Expectation values and uncertainty principle for infinite square well
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Time Evolution (Fourier's Trick)
Determining wavefunction from initial state
Video Lecture
Griffiths problems 2.8 & 2.9
Determining a wavefunction given its initial state using Fourier's trick
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Harmonic Oscillator Normalization
Normalizing $\psi_0$ and $\psi_1$
Video Lecture
Griffiths QM Problems 2.11 and 2.12
Normalizing the quantum harmonic oscillator's wavefunction
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
First Excited State & Orthogonality
Normalizing $\psi_1$ and proving $\langle\psi_0|\psi_1\rangle = 0$
Video Lecture
Griffiths QM 2.13
Normalizing first excited state, showing orthogonality of states
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Harmonic Oscillator Expectation Values
Determining $\langle x \rangle$, $\langle p \rangle$, and uncertainties
Video Lecture
Griffiths QM problem 2.14
Determining expectation values and uncertainty for harmonic oscillator
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Expectation Values for Given Wavefunction
Finding expectation values of harmonic oscillator with known $\psi$
Video Lecture
Griffiths QM problem 2.17
Given wavefunction find expectation values of harmonic oscillator
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Hermite Polynomials
Working with Hermite polynomial properties and identities
Video Lecture
Griffiths QM Problem 2.18/2.17
Hermite Polynomials exercises
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Exponential vs Sine/Cosine Solutions
Choosing appropriate solution forms for boundary conditions
Video Lecture
Griffiths QM Problem 2.19
Choosing exponential vs cosine/sine solutions
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Plancherel Theorem
Proving $\int |f(x)|^2 dx = \int |F(k)|^2 dk$
Video Lecture
Griffiths QM Problem 2.20
Proving Plancherel Theorem
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Uncertainty Principle for Free Particle
HARD PROBLEMShowing $\sigma_x \sigma_p \geq \hbar/2$ for free particle evolution
Video Lecture
Griffiths QM Problem 2.22
Uncertainty Principle for Free Particle
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Double Delta Potential Well (Using Trick)
Determining bound states for $V(x) = -\alpha[\delta(x+a) + \delta(x-a)]$
Video Lecture
Griffiths QM problem 2.26
Determining bound states of double delta-potential well (using trick)
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Transmission Coefficient (Double Delta)
Finding transmission coefficient for double delta potential
Video Lecture
Griffiths QM 2.27 Solution
Finding Transmission coefficient for double delta potential
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Finite Square Well Bound States
Determining bound states (easy way!)
Video Lecture
Griffiths QM Problem 2.28
Determining Bound States of the Finite Square Well (Easy way!)
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Scattering States (Finite Square Well)
Determining scattering states for finite square well
Video Lecture
Griffiths QM Problem 2.31 Solution
Determining the Scattering States for the finite square well
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Rectangular Potential Barrier
Transmission coefficient for all 3 cases
Video Lecture
Griffiths QM problem 2.32
Transmission coefficient for rectangular potential barrier (All 3 cases!)
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Step Potential Barrier
Transmission and reflection coefficients
Video Lecture
Griffiths QM 2.33 Solution
Transmission and reflection Coefficient for Step Potential Barrier
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Scattering Matrix Method
Using S-matrix to find bound states of delta potential
Video Lecture
Griffiths QM 2.34 Solution
Using the Scattering Matrix to find Bound States of Delta Potential
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
QHO Expectation Values (nth State)
Finding expectation values for nth stationary state
Video Lecture
Griffiths QM Problem 2.37 (3rd edition)
Find expectation values for nth stationary state of QHO
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Uncertainty Principle (Traveling Wave)
HARD PROBLEMChecking uncertainty principle for traveling wave packet
Video Lecture
Griffiths QM problem 2.40 (3rd ed)
Checking Uncertainty Principle for Traveling Wave Packet (HARD)
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Reflection Off a Cliff
Probability of reflection off of a cliff potential
Video Lecture
Griffiths QM Problem 2.41 (3rd edition) Solution
Probability of reflection off of a cliff
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
No Degenerate Bound States in 1D
Proving no degenerate bound states exist in one dimension
Video Lecture
Griffiths QM Problem 2.42 (3rd Edition)
Proving that there can be no degenerate bound states in 1-D
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
1D Degeneracy (Bead on Circle)
Bead of mass M sliding around a circle - understanding degeneracy
Video Lecture
Griffiths QM Problem 2.43
Understand 1-D Degeneracy with a bead of mass M that slides around circle
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Harmonic Oscillator Potential
VERY HARDVery challenging harmonic oscillator potential problem
Video Lecture
Griffiths QM problem 2.45 (3rd edition)
VERY HARD Harmonic Oscillator Potential Problem
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Delta Potential Well
Solving Schrödinger equation for delta potential well
Video Lecture
Griffiths Problem 2.46 (3rd edition)
Solving Schrodinger Eq for delta potential well
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Moving Delta Function
Solution for moving delta function and expectation of Hamiltonian
Video Lecture
Griffiths QM 2.47 (3rd edition)
Solution for the moving delta function and expectation of Hamilton
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
QM Exam #1
Comprehensive exam: Schrödinger equation, delta potential, infinite square well
Video Lecture
Quantum Mechanics Exam #1 (HARD)
Schrödinger Equation, delta potential, Infinite Square Well
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Chapter 3: Formalism
Mathematical structure of quantum mechanics, Hilbert spaces, and linear algebra
Gram-Schmidt Procedure
The EASIEST explanation of the Gram-Schmidt orthogonalization procedure
Video Lecture
The EASIEST Explanation of the Gram-Schmidt Procedure (Griffiths QM 3rd ed. Problem 3.4)
Gram-Schmidt Procedure
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Chapter 4: Three-Dimensional Systems
Infinite Cubical Well
Solving for energy states in 3D cubic box
Video Lecture
Griffiths QM Problem 4.2 (3rd edition) Solution
Solving the Infinite Cubical Well FULLY EXPLAINED
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Constructing Spherical Harmonics
For $l=m=0$ and $l=2, m=1$
Video Lecture
Griffiths QM Problem 4.3
Constructing Spherical Harmonics for l=m=0 and l=2, m=1
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
The OTHER Angular Solution
Alternative solution to the angular equation
Video Lecture
Griffiths Problem 4.4 (3rd ed) Solution
The OTHER Solution to the Angular Equation
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Finding Spherical Harmonics
For $l=m$ and $l=3, m=2$ with verification
Video Lecture
Griffiths QM Problem 4.5 (3rd edition)
Finding Spherical Harmonics for l=m and l=3, m=2 & checking
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Legendre Polynomial Orthonormality
Deriving orthonormality relation for Legendre polynomials
Video Lecture
Griffiths QM Problem 4.6
Deriving Orthonormality Relation for Legendre Polynomials
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Spherical Bessel & Neumann Functions
Constructing spherical Bessel and Neumann functions for $l=2$
Video Lecture
Griffiths QM (3rd edition) Problem 4.7 Solution
Construct spherical Bessel & Neumann functions l=2
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Infinite Spherical Well
Solving infinite spherical well for $l=1$
Video Lecture
Griffiths QM Problem 4.8
Infinite Spherical Well for l=1
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Finite Spherical Well
Solving the finite spherical well for $l=0$
Video Lecture
Griffiths QM Problem 4.9 (3rd ed.)
Solving the FINITE Spherical Well for l=0
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Radial Wave Functions (Recursion)
Finding radial wave functions using recursion formula for H atom
Video Lecture
Griffiths QM Problem 4.10 (3rd ed.)
Finding Radial Wave Functions Using Recursion Formula | H atom
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Normalizing H Atom Wavefunctions
Normalizing $R_{20}$ and $R_{21}$ for hydrogen atom
Video Lecture
Griffiths QM Problem 4.11 (3rd ed.)
Normalizing R20 and R21 | Hydrogen Atom
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Laguerre Polynomials & Recursion
Radial equation using Laguerre polynomials and recursion
Video Lecture
Griffiths QM Problem 4.12 (3rd ed.)
Radial Equation using Laguerre Polynomials and recursion
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Expectation Values (H Atom)
Finding expectation values for hydrogen atom
Video Lecture
Griffiths QM Problem 4.13 (3rd ed.)
Finding Expectation Values for Hydrogen Atom
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Electron Inside the Nucleus?
Can an electron be inside the nucleus? Probability calculation
Video Lecture
Griffiths Intro to QM Problem 4.14 FULL SOLUTION
Can an Electron Be INSIDE The Nucleus?
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Radial Wavefunction for $l=n-1$
Proving radial wavefunction and finding expectation values for $l=n-1$
Video Lecture
Griffiths QM 4.15 Solution
Proving Radial Wavefunction and finding expectation values for l=n-1
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Ladder Operator Normalization
Determining normalization constant for ladder operators
Video Lecture
Griffiths QM 4.19
Determining normalization constant for ladder operators
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Angular Momentum Commutators
Proving commutators of angular momentum operators
Video Lecture
Griffiths QM Problem 4.20
Proving Commutators of Angular Momentum
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Uncertainty Principle for Spin
Checking uncertainty principle for a spin state
Video Lecture
Griffiths QM problem 4.28
Checking uncertainty principle for a spin state
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Chapter 6: Approximation Methods
Time-independent and time-dependent perturbation theory, variational methods
ISW with Delta Bump
First order correction of energy levels of infinite square well with delta function perturbation
Video Lecture
Solving Griffith's problem 6.1
First order correction of energy levels of ISW with delta bump
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Orthogonality & "Good" States
Proving orthogonality and energy for "good" states in perturbation theory
Video Lecture
Griffiths QM Problem 6.6 Solution
Proving Orthogonality and Energy for Good states
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Particle in Circular Wire
Wavefunction and energy for particle in circular wire of length $L$
Video Lecture
Griffiths QM Problem 6.7 Solution
Wavefunction & Energy, for particle in circular wire of length L
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Cubical Well with Delta Potentials
Energy levels of infinite cubical well with delta potentials (degenerate perturbation theory)
Video Lecture
Problem 6.8 Griffiths
Energy levels of infinite cubical well with delta potentials (degenerate PT)
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Understanding Perturbation Theory
The best problem to truly understand perturbation theory
Video Lecture
Griffiths QM Problem 6.9 Solution
THE BEST PROBLEM TO UNDERSTAND PERTURBATION THEORY
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Relativistic Correction (QHO)
Relativistic correction for quantum harmonic oscillator
Video Lecture
Griffiths QM 6.13 (3d edition) Solution
Relativistic Correction for Quantum Harmonic Oscillator
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Fine Structure Formula
Deriving the fine structure formula (also 6.17 in 2nd edition)
Video Lecture
Griffiths QM problem 6.15 (3rd edition)
Deriving fine structure formula
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Balmer Line Corrections
Corrections to the Balmer lines (also 6.18 in 2nd edition)
Video Lecture
Griffiths QM problem 6.16 (3rd edition)
Corrections to the Balmer lines
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Exact Fine Structure Expansion
Expanding exact form of fine structure (also 6.19 in 2nd edition)
Video Lecture
Griffiths QM problem 6.17 (3rd edition)
Expand exact form of fine structure
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Zeeman Effect (n=2)
Zeeman effect for n=2 hydrogen (also 6.21 in 2nd edition)
Video Lecture
SOLUTION to Griffiths QM problem 6.19 (3rd edition)
Zeeman effect for n=2
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Strong Field Zeeman Effect
Strong field Zeeman effect derivation (also 6.22 in 2nd edition)
Video Lecture
Strong Field Zeeman effect derivation + Griffiths Intro to QM 6.20 (3rd edition)
Strong Field Zeeman Effect
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Strong Field Zeeman Explained
Strong field Zeeman effect explained (also 6.23 in 2nd edition)
Video Lecture
Griffiths Intro to QM problem 6.21 (3rd edition)
Strong field Zeeman Explained
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Hyperfine Structure of Hydrogen
Deriving hyperfine structure of hydrogen atom
Video Lecture
Deriving Hyperfine Structure of Hydrogen atom + Griffiths 6.25 (3rd edition)
Hyperfine Structure of Hydrogen
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Hyperfine Splitting (Exotic Atoms)
Hyperfine splitting for muonic H, positronium, muonium (also 6.28 in 2nd edition)
Video Lecture
Griffiths QM 6.26 (3rd ed)
Hyperfine Splitting for Muonic H, Positronium, Muonium
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Feynman-Hellmann Theorem
Proving the Feynman-Hellmann theorem with harmonic oscillator example
Video Lecture
Griffith's QM problem 6.27
Proving the Feynman-Hellmann theorem with harmonic oscillator example
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Kramer's Relation
Using Kramer's relation to find expectation value of $r^3$
Video Lecture
Griffiths Introduction to QM Problem 6.30
Using Kramer's relation to find expectation value of r^3
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Stark Effect
The Stark effect for hydrogen (also 6.36 in 2nd edition)
Video Lecture
Solution to Griffiths Introduction to QM Problem 6.31 (3rd edition)
Stark effect
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Chapter 7: The Variational Principle
Variational methods for approximating ground state energies
Linear & Quartic Potentials
Using variational principle with $V(x)=a|x|$ and $ax^4$
Video Lecture
Griffiths Intro to QM problem 7.1 (3rd edition)
Using variational principle with V(x)=a|x| and ax^4
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
QHO Variational Method
Using variational principle for QHO with $\psi=1/(x^2+b^2)$
Video Lecture
Griffiths QM Problem 7.2 (3rd edition)
Using Variational Principle for QHO with psi=1/(x^2 +b^2)
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
H Ground State (Gaussian)
Ground state energy of hydrogen using $Ae^{-br^2}$ trial function
Video Lecture
Griffiths Intro to QM 7.11 (3rd edition) solution
Ground state energy of H using Ae^(-br^2)
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Yukawa Potential
Hydrogen atom with Yukawa potential using variational principle
Video Lecture
Griffiths Problem 7.12 (3rd edition) Solution
Hydrogen Atom Yukawa Potential Variational principle
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Variational + Perturbation
Application of variational principle and perturbation theory together
Video Lecture
Griffiths QM Problem 7.13 solution
Application of Variational Principle and Perturbation Theory
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Chapter 8: The WKB Approximation
Semiclassical approximation methods for quantum mechanics
🧬 Biophysics Connection: WKB methods are essential for understanding quantum tunneling in proteins — including proton transfer in enzyme catalysis, hydrogen bond dynamics, and conformational transitions over energy barriers.
ISW with Shelf
Bound state energies for infinite square well with "shelf" using WKB
Video Lecture
Griffiths QM Problem 8.1
Bound state Energies for Infinite Square well with shelf (WKB)
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
WKB Formula Derivation
Deriving WKB formula by expanding powers of $\hbar$
Video Lecture
Griffiths QM Problem 8.2 (3rd edition)
Deriving the WKB formula by expanding powers of hbar
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Connection Formulas
Deriving WKB connection formulas for downward sloping potential
Video Lecture
Griffiths QM Problem 8.9
Deriving the WKB Connection Formulas for a Downward Sloping Potential
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Transmission Coefficient
Transmission coefficient for barrier with sloping walls
Video Lecture
Griffiths Intro to QM Problem 8.10 Solution
Transmission Coefficient for Barrier with Sloping Walls
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Power Law Potential
Find energies for $V(x)=\alpha|x|^\nu$ using WKB
Video Lecture
Griffiths QM Problem 8.11 Solution
Find Energies for V(x)=alpha*|x|^nu WKB Approx. - HARD PROBLEM
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Tough WKB Integrals
Very hard WKB problem with tough integrals
Video Lecture
Griffiths QM Problem 8.12 Solution
Try this VERY hard WKB Problem with TOUGH Integrals!
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Logarithmic Potential
Energy of $V=V_0\ln(r/a)$ using WKB approximation
Video Lecture
Griffiths QM 8.13 Solution
Energy of Logarithmic Potential (V=V_0 ln(r/a)) using WKB Approximation
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Hydrogen via WKB
How to solve the hydrogen atom in 20 minutes using WKB!
Video Lecture
How to solve the Hydrogen Atom in 20 minutes (Using WKB Approximation) Griffiths QM 8.14
Solving Hydrogen Atom using WKB
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
The Ultimate WKB Problem
The ULTIMATE WKB problem - hardest one yet!
Video Lecture
Griffiths Intro to QM - Problem 8.15
The ULTIMATE WKB Problem - HARDEST ONE YET
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
Chapter 9: Time-Dependent Perturbation Theory
Time-dependent perturbations and transition probabilities
H in Time-Dependent E Field
Hydrogen atom in time-dependent electric field
Video Lecture
Griffiths Intro to QM Problem 9.1
Hydrogen Atom in Time dependent Electric field
💡 Tip: Watch at 1.25x or 1.5x speed for efficient learning. Use YouTube's subtitle feature if available.
📚 87 problems added so far...
1 more Griffiths QM problem solution will be added to reach 88!