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Quantum Physics

Visualise the counterintuitive world of quantum mechanics — from wavefunction collapse at the double slit to electron tunnelling through potential barriers.

7+ simulations Canvas 2D · WebGL Schrödinger · Orbitals · QFT

Category Simulations

Each simulation runs fully in the browser — no server, no installation

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★☆☆ Easy Popular
Double-Slit Experiment
Watch an interference pattern build up one photon at a time. Toggle the "which-path" detector to collapse the interference and demonstrate wave–particle duality interactively.
Wave Optics Interference Canvas 2D
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★★★ Advanced New
Schrödinger Equation
Time-evolution of a Gaussian wave packet in 1-D via the Crank–Nicolson scheme. Draw custom potential wells, barriers and harmonic oscillators. Watch the probability density breathe and split at barriers.
Crank-Nicolson Wavefunction PDE
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★★☆ Moderate
Quantum Tunnelling
A particle wavepacket hits a potential barrier — some of it tunnels through even though classical physics forbids it. Adjust barrier width and height, measure transmission probability in real time.
Tunnelling Wavefunction Potential Well
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★★★ Advanced New
Hydrogen Atom Orbitals
3-D volumetric rendering of hydrogen electron probability densities. Choose any (n, ℓ, m) quantum numbers and rotate the orbital. Isosurface display shows the nodal structure.
Three.js Spherical Harmonics 3D
★★☆ Moderate New
Photoelectric Effect
Shine photons of variable frequency on a metal surface and observe electron ejection. Interactive Einstein-model graph shows how stopping voltage depends on frequency — not intensity.
Photons Energy Quanta Canvas 2D
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★★★ Advanced New
Quantum Spin & Bloch Sphere
Visualise qubit states on the Bloch sphere. Apply Pauli gates and arbitrary rotations; watch superposition and decoherence as you add simulated noise. Ideal for understanding single-qubit quantum computing.
Bloch Sphere Three.js Qubit
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★★★ Advanced New
Quantum Field Lattice
A 2-D scalar field on a lattice evolves via the Klein–Gordon equation. Drag to create field excitations ("particles") and watch them propagate, scatter and annihilate.
QFT Klein-Gordon Lattice
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New ★★★ Advanced
Grover's Algorithm
Quantum search algorithm with O(√N) speedup. Visualise amplitude amplification iterations on a Bloch-sphere representation as the algorithm finds the target state.
Quantum Computing Amplitude Amplification Canvas 2D
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New ★★☆ Moderate
Qubit — Bloch Sphere
Interactive 3D Bloch sphere for a single qubit. Apply X, Y, Z, H and phase gates — watch the state vector rotate and understand superposition visually.
Quantum Gates Three.js Bloch Sphere
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New ★★★ Advanced
Quantum Entanglement
Visualise Bell states and EPR correlations. Measure entangled qubits and watch correlated outcomes — explore why Einstein called it "spooky action at a distance."
Bell States EPR Canvas 2D
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★★☆ Moderate New
Quantum Harmonic Oscillator
Explore energy levels Eₙ = ℏω(n+½) and wavefunctions ψₙ(x) built from Hermite polynomials. Toggle between ψₙ and probability density, overlay all levels n ≤ 5, and step through quantum numbers 0–10.
Hermite Polynomials Energy Levels Canvas 2D
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★☆☆ Easy New
Heisenberg Uncertainty Principle
Drag the position-width slider and watch momentum spread grow in real time. Both |ψ(x)|² and |φ(p)|² are shown side-by-side — Δx·Δp stays ≥ ℏ/2, no matter what.
Uncertainty Gaussian Packet Canvas 2D
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★★☆ Moderate New
Wave Packet Interference
Two Gaussian packets launched toward each other interfere constructively and destructively inside a 1-D box. Vary momenta to produce beats, standing waves and quantum revivals.
Interference Quantum Beats Split-Operator
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★★☆ Moderate New
Quantum Circuit Simulator
Click-to-place gate builder for up to 3 qubits. Supports H, X, Y, Z, S, T, CNOT and SWAP gates. State vector and probability histogram update instantly. Presets: Bell state, GHZ, Grover search.
Quantum Gates State Vector Canvas 2D
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★☆☆ Easy New
BB84 Quantum Key Distribution
Step through the BB84 QKD protocol: Alice sends photons in random bases, Bob measures, they sift matching bases to form the secret key. Enable eavesdropper Eve and watch the quantum bit error rate spike.
BB84 Quantum Cryptography QKD

Related Articles

The mathematics and theory behind quantum simulations

About Quantum Mechanics Simulations

Wave functions, tunnelling, and superposition — visualised

Quantum mechanics simulations solve the Schrödinger equation numerically to show how particles behave when quantum effects dominate. The 1D wave packet spreads and tunnels through barriers that classical particles could never penetrate. The hydrogen orbital visualiser renders electron probability clouds (s, p, d orbitals) as 3D density plots from the exact analytic solution. The double-slit simulation shows how a single-particle distribution builds up the famous interference pattern one click at a time.

These simulations use split-operator Fourier methods and real-space finite-difference integration to propagate quantum states accurately. By adjusting barrier width, particle energy, or orbital quantum numbers you directly observe the counterintuitive predictions of quantum theory — quantised energy levels, wave-function collapse, zero-point energy, and the complementarity of position and momentum.

Quantum physics simulations make abstract formalism visceral. The double-slit experiment — which Richard Feynman called 'the only mystery' of quantum mechanics — shows wave-particle duality in an undeniable way. Hydrogen orbital shapes are not just pretty pictures: they are the real probability clouds that chemists use to predict molecular bonding geometry, reaction pathways, and spectroscopic signatures. These simulations bridge the gap between textbook equations and physical intuition.

All Categories

Key Concepts

Topics and algorithms you'll explore in this category

Wave FunctionProbability amplitude |ψ|² and Born rule
Schrödinger EquationTime-dependent and time-independent forms
Quantum TunnellingTransmission through classically forbidden barriers
Double-Slit ExperimentWave-particle duality and interference pattern
Hydrogen OrbitalsPrincipal, angular, and magnetic quantum numbers
Spin & EntanglementBloch sphere, Bell states, and EPR correlations

🧪 Test Your Quantum Knowledge

5 questions — wave functions, tunnelling, and more

Frequently Asked Questions

Common questions about this simulation category

What quantum mechanics topics are simulated?
Double-slit interference, Schrödinger equation wavepacket propagation, quantum tunnelling (WKB), hydrogen atom orbitals (spherical harmonics), harmonic oscillator eigenstates, and basic spin/entanglement on the Bloch sphere.
How is quantum tunnelling simulated?
The time-dependent Schrödinger equation (TDSE) is solved with a split-operator FFT method. A Gaussian wavepacket is evolved through a potential barrier — you can adjust barrier height and width and watch the transmitted and reflected fractions.
Can I visualise hydrogen atom orbitals?
Yes — the simulation renders the probability density |ψnlm|² as a 3D volume or 2D cross-section. You can select any (n, l, m) combination and rotate the orbital.