Category: Index
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Johnson-Nyquist Noise
Introduction Johnson-Nyquist Noise, also known as thermal noise or Johnson noise, is the electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical conductor at equilibrium. It’s an essential consideration in electronics and signal processing and was first measured accurately by John B. Johnson and then theoretically analyzed…
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Kondo Effect
Introduction The Kondo effect, named after the Japanese physicist Jun Kondo who first explained it in 1964, is a peculiar phenomenon in solid-state physics where the electrical resistance of a metal, containing a small number of magnetic impurities, increases as the temperature decreases. This behavior contradicts the typical understanding that the resistance of metals decreases…
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Kibble-Zurek Mechanism (KZM)
Introduction The Kibble-Zurek Mechanism (KZM) is a theoretical framework in the field of non-equilibrium physics that aims to explain the emergence of topological defects during phase transitions. Proposed by Tom Kibble and Wojciech Zurek, the KZM explains how the universe behaves when transitioning from a high symmetry phase to a low symmetry phase, a phenomenon…
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Le Chatelier’s Principle
Introduction Le Chatelier’s Principle is a fundamental concept in physical chemistry that describes the behavior of dynamic equilibrium systems when subjected to external changes. Named after French chemist Henry Le Chatelier, this principle predicts how changes in conditions such as temperature, pressure, or concentration of components will affect the position of the chemical equilibrium. Statement…
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U(1) Gauge Theory
Introduction U(1) gauge theory forms the cornerstone of quantum electrodynamics (QED), which describes the interactions between charged particles and electromagnetic fields. The “U” in “U(1)” stands for “unitary”, while the “1” signifies that the transformation involves a 1-dimensional unitary group. In essence, U(1) gauge theory is a mathematical framework that incorporates the principle of local…
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Cooper Pairs
Introduction In the field of superconductivity, Cooper pairs play a fundamental role. Named after physicist Leon Cooper, a Cooper pair is a bound state of two electrons (or other fermions) with opposite momenta (i.e., moving in opposite directions) and opposite spins, effectively forming a boson. Formation of Cooper Pairs Electrons in a material are usually…
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Inverse Square Law
Introduction In physics, the inverse square law refers to any physical quantity or strength that is inversely proportional to the square of the distance from the source of that physical quantity. This law applies to diverse phenomena, from gravity and electric fields to light and sound. Mathematical Formulation of an Inverse Square Law Mathematically, the…
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Plasma
Introduction Plasma, often referred to as the “fourth state of matter”, is a distinct phase separate from solids, liquids, and gases. This state is reached when a gas is provided with sufficient energy that its atoms dissociate into a soup of ions and free electrons. This ionized state of matter exhibits unique properties, including high…
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Reynolds Number
Introduction The Reynolds number is a fundamental concept in fluid dynamics, enabling us to categorize the flow of fluids and predicting the onset of turbulence. Named after Osborne Reynolds, this dimensionless quantity measures the ratio of inertial forces to viscous forces. The Reynolds Number: Concept and Applications The Reynolds number plays a pivotal role in…
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Thomas Precession
Introduction Thomas precession, a relativistic phenomenon predicted by Llewellyn Thomas in 1926, has significant implications for the study of high-speed particle physics. It describes a correction factor applied to the motion of a spinning particle when observed from an inertial frame of reference, which is central to special relativity and quantum mechanics. Fundamental Concepts Thomas…