Quantum Experiments

Quantum Experiments · Quantum Research Center

Quantum Experiments

See the apparatus. Follow the argument. Question the evidence.

From individual detector clicks to Wigner’s friend, learn how laboratory experiments and thought experiments constrain our explanations of the quantum world.

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24 interactive models72 solved problems1 reproducible capstone

How to use this course

Begin with basic algebra, waves, and probability. Chapters 1–12 introduce amplitudes and experimental reasoning in context; the later chapters use two-component vectors, simple matrices, and tensor products, explained through examples. Optional sensing derivations use elementary differentiation. Quantum Foundations and Interpretations of Quantum Mechanics offer deeper mathematical and philosophical treatments.

Every chapter develops a question, an apparatus or thought scenario, a quantitative prediction, and the limits of the inference. Each includes an interactive visualization, a worked example, three problems with hints and solutions, and sources. Read sequentially or follow an experiment from the contents below.

The visualizations are idealized teaching models. Detector clicks and the downloadable capstone scan are labelled synthetic; they are not laboratory measurements. Thought scenarios explicitly separate controlled quantum memories from human observers. No interpretation is presented as experimentally selected by the animation.

Use Play for a parameter sweep or a sequence of synthetic trials. Pause to inspect a state, Step to advance without continuous motion, and Reset to return to the initial setup. Nothing autoplays. Controls work with a keyboard, values are available in tables, and the static explanations remain readable without JavaScript or a network connection.

This is a complete first teaching edition, with developed lessons throughout. The capstone asks you to report a reproducible result with uncertainty and limitations. Advanced results are identified by their assumptions and linked sources; the course does not claim full proofs of every general theorem.

I · Observations and models

  1. 01From Clicks to EvidenceHow does a detector click become evidence for a physical claim?
  2. 02Energy Comes in StepsHow do spectra and photoelectric measurements reveal energy scales?
  3. 03Matter Waves and the Double SlitHow can separate detection events form an interference pattern?
  4. 04Stern–Gerlach and Sequential MeasurementsWhy does inserting a different measurement change later outcomes?
  5. 05Polarization and Three FiltersWhy can adding a polarizer increase transmission through crossed filters?
  6. 06Single Photons and CoincidencesWhat makes a source of light nonclassical?

II · Paths, information, and time

  1. 07Mach–Zehnder: Adding AlternativesHow can two individually random beam splitters give a certain output?
  2. 08Einstein’s Recoiling SlitCan a movable slit record a path without changing interference?
  3. 09Wheeler’s Delayed ChoiceDoes choosing the measurement late change what happened earlier?
  4. 10Quantum Erasure and Conditional FringesWhere are the fringes hiding when path information is available?
  5. 11The Elitzur–Vaidman Bomb TesterCan an object be detected in a trial in which it absorbs nothing?

III · Control and reconstruction

  1. 12Tunnelling Through a BarrierHow can transmission occur when the particle energy is below a barrier?
  2. 13Rabi Oscillations and Coherent ControlHow does a pulse prepare a chosen quantum state?
  3. 14Ramsey, Decoherence, and EchoHow can phase evolution reveal coherence and its loss?
  4. 15Reconstructing a Quantum StateHow can several incompatible measurements describe one preparation?

IV · Correlations and constraints

  1. 16Two-Photon Interference and EntanglementWhat changes when two indistinguishable photons meet?
  2. 17EPR, Bohm, and Bell TestsWhich assumptions about separated systems can correlations test?
  3. 18GHZ and ContextualityCan every possible measurement have a context-independent value?
  4. 19Teleportation and Entanglement SwappingWhat is transferred when a quantum state is teleported?

V · Records and observers

  1. 20Schrödinger’s Cat and the Measurement ProblemDoes a correlated wavefunction describe one observed outcome?
  2. 21Wigner’s FriendCan an observer and an outside experimenter assign different states consistently?
  3. 22Extended Friends and ConsistencyWhich assumptions make different observers’ certainty claims conflict?

VI · From models to investigation

  1. 23Quantum Sensing and Atomic ClocksHow does a phase become a precise estimate of a field or frequency?
  2. 24Capstone: Audit an Interference ClaimCan you turn counts into a reproducible, appropriately limited conclusion?

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