Book Contents
Book Contents for: d.i.y. Quantum Physics – Exploring Quantum Physics Through Hands-On Projects by David Prutchi and Shanni R. Prutchi
The Introduction proposes to build an intuitive understanding of the principles behind Quantum Mechanics through hands-on construction and replication of the original experiments that led to our current view of the quantum world.
A Disclaimer and Warnings section provides a legal disclaimer which identifies the information contained within to be solely educational in nature. This section also addresses specific precautions that the reader must take when working with dangerous materials and equipment such as chemicals, high-voltage power supplies, lasers, radioactive isotopes, and vacuum vessels.
The Prologue, subtitled “Your Quantum Physics Lab,” discusses the basic tools and instruments needed to construct the projects in the book. It also suggests low-cost sources and alternatives for these materials.
Chapter I – Light as a Wave – familiarizes the reader with the way 19th Century physicists understood light. Understanding the classical view of light is key to appreciating why Quantum Mechanics would stir such a revolution in physics. In the first chapter we perform the experiments that seemed to confirm the correctness of the classical understanding of light’s wave nature, but we also look at some of the problems raised by these same experiments. Projects in this chapter include:
- Waves in a ripple tank
- Young’s double-slit experiment
- Automatic interference-pattern scanner
- Microwave optics (polarization, 2-slit interference, Doppler Effect).
In Chapter II – Light as Particles – we replicate the photoelectric current and blackbody radiation experiments that produced data that could not be reconciled with the theoretical explanations of Classical Physics. We study the sweeping explanations proposed by Max Planck and Albert Einstein to resolve this issue. Projects in this chapter include:
- Measurement of blackbody radiation
- Photoelectric Effect and its dependence on wavelength and amplitude
- Delay in photoelectric current generation
- Photomultiplier tubes
- PMT power supplies and signal processors
- Detection of individual photons with a PMT
Chapter III – Atoms and Radioactivity – gets us into atomic physics and radioactivity. We build equipment to perform the experiments that gave us our current view of atoms and that brought chemistry into the modern era. We place special emphasis on Thomson’s discovery of the electron in preparation to discussing electron interference, as well as on Rutherford’s discovery of the nucleus, and the reason why Rutherford’s atomic model could not be explained without quantization. Projects in this chapter include:
- Vacuum pump and vacuum gauging
- A vacuum tube “Lego” set for electron beam experiments
- Very high voltage power supply for electron beam experiments
- Phosphor screens
- Glow tubes, cathode-ray tubes, and the Maltese Cross tube
- Reproduction of Thomson’s first, second, and third experiments with cathode rays
- Measuring e/m through Hoag’s method, and using a tuning-eye tube
- Geiger-Müller counter and scintillation probe
- Penetrating power of alpha, ß, and Gamma rays
- Magnetic deflection of ß rays
- Spark counter and the ionizing power of a radiation
- Measurement of Rutherford’s alpha-particle scattering
In Chapter IV – The Principle of Quantum Physics – we look at quantization – the core principle behind Quantum Mechanics – and at some of the ways in which it successfully tackled the major pitfalls of 19th Century Classical Physics. We concentrate on Bohr’s model of the atom, especially on how quantizing the electron’s angular momentum yields exact predictions for hydrogen’s emission lines. Projects in this chapter include:
- Spectrum tubes for emission spectroscopy
- Diffraction-grating spectroscope
- Digital processing of emission spectra
- Measurement of Planck’s constant using LEDs
In the experiments of Chapter V –Wave/Particle Duality – we take advantage of technology that was not available to the pioneers of Quantum Mechanics to show that both light and material objects can behave both waves and particles. We concentrate on the measurement of two-slit interference patterns produced one particle at a time, and discuss the type of experiment as determinant of whether particle-like or wave-like behaviors are observed. Projects in this chapter include:
- Multichannel analyzer and Gamma-ray spectral analysis
- Observing the Compton Effect
- Two-slit interference with single photons
- Electron diffraction and de Broglie’s matter waves
- Transmission electron microscopy
Chapter VI – The Uncertainty Principle – introduces Heisenberg’s Uncertainty Principle – the concept that we cannot measure the exact position and momentum of an object at the same time. We demonstrate that this is not due to imprecise measurements. Rather, the blurring of these magnitudes is a fundamental property of nature with truly mind-boggling implications about our view of reality. Projects in this chapter include:
- Fourier analysis and the Uncertainty Principle
- Single-slit diffraction demonstration of the Uncertainty Principle
- Single-slit diffraction with microwave photons
In Chapter VII – Schrödinger (and his Zombie Cat) – we discuss Schrödinger’s equation and its practical applications. We demonstrate the use of Schrödinger’s equation as a solution of the particle-in-a-box problem to predict the emission wavelength from quantum dots. We then demonstrate quantum tunneling and quantum superposition as features captured by Schrödinger’s equation. Projects in this chapter include:
- Quantum dots
- Quantum tunneling
- Preparing quantum states in quantum optics
- Quantum analysis of beamsplitters
- Coincidence counting
- Mach-Zehnder Interferometer
- Mach-Zehnder Interferometer with single photons
- Which-way experiments and quantum erasers
Lastly, Chapter VIII – Entanglement – looks at demonstrations of the existence of entanglement. This quantum property is so uncanny that it caused Einstein mock it by calling it “spooky action at a distance.” Entanglement was proven only in the 1980s, and its deep implications are causing radical changes in the way we view our world. We also look at technologies that are being developed as a consequence of understanding the role of information in Quantum Mechanics, and end the book by peeking at how entanglement is quickly making strides into areas that were recently the domain of pure science-fiction, enabling quantum teleportation, unbreakable cryptography, and quantum computing. Projects in this chapter include:
- Generation of entangled photon pairs
- A SPAD-based photon detector for quantum optics experiments
- High-speed coincidence counting
- Violation of Bell’s inequalities
- Quantum random number generation
- Qubits and quantum information