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Visuals: Unit 8


2D Shear
Simple rules are written that if randomly placed particles touch when a system shears they are moved to a new position when the system is cycled back.
Critical Points
A critical point is the point at which the boundary that separates two stable states of matter disappears.
Fluctuations and Temperature
Coleman could see a very direct and simple relationship with the spectrum of the fluctuations and the temperature of the material.
High Temperature Superconductors
In the first superconducting material, mercury was cooled to 4 K and 75 years later scientists made a giant leap forward as they discovered many related materials that superconduct at temperatures well above 90 K.
Neutron Scattering
As neutrons come in contact with magnetic atoms in a material, they scatter, losing kinetic energy. This excites the magnetic fluctuations in the material.
Periodic Table: A Canvas
And the canvas that we work with is the canvas of the periodic table. We have something like 92 different elements to play with.
Quantum Critical
CeCu6Au is "quantum critical" when it fluctuates between magnetic and metallic phases. Coleman wants to understand this kind of emergent behavior.
Superconductor Properties
Superconductors carry electrical current without resistance and are almost perfect diamagnets (a more fundamental aspect of their behavior), in that they can screen out external magnetic fields within a short distance.
Taylor's Experiment 1
Like G.I Taylor, they placed their colloid, the fluid and the particles, inside a couette cell, which consists of a cylinder with another cylinder inside it.
Taylor's Experiment 2
When Pine and Gollub ran this experiment they thought that rotating the cylinder would shear the fluid, causing some particles to collide.


Bardeen, John
John Bardeen, with Leon Cooper and Robert Schrieffer, was awarded the Nobel Prize for his work on the BCS theory.
Bohm, David
David Bohm's life involved a series of contradictions. Refused security clearance for work on the atom bomb during World War II, he made critical contributions to the development of the bomb.
Crab Nebula
This recent image from the Chandra x-ray telescope shows the Crab Nebula, the remnant of a supernova explosion seen on earth in 1054 AD that accompanied the formation of a rapidly rotating neutron star at its center.
Highly Directional Semiconductor Lasers
Highly directional semiconductor lasers are quantum cascade lasers patterned with a plasmonic collimator which greatly reduces the divergence in the vertical direction.
Landau, Lev
Landau impacted theoretical physics over much of the 20th century.
London, Fritz
Fritz London was a seminal figure in the early days of quantum mechanics through his pioneering work on the chemical bond, the measurement problem, and to our understanding of superfluidity and superconductivity.
Meissner Effect
A photograph such as this of a levitating magnet is arguably the iconic image for superconductivity.
Mott, Nevill
Nevill Mott was a world leader in atomic and solid-state physics during a career in theoretical physics that spanned over sixty years.
Nanowires are crystalline fibers with emergent behaviors expected to be used for nanoscale applications.
Onsager, Lars
Lars Onsager, a physical chemist and theoretical physicist who possessed extraordinary mathematical talent and physical insight.
Oppenheimer, Robert
The first director of the Los Alamos National Laboratory, Robert Oppenheimer (ca. 1944) was a brilliant theoretical physicist and inspired teacher who became famous for his remarkably effective leadership of the Manhattan Project.
Scanning Tunneling Microscope
Left: A scanning tunneling microscope (STM) is a powerful instrument for imaging surfaces at the atomic level. Right: Inhomogeneous energy gaps in BSCCO.
Superfluid Motion without Resistance
Like the condensate, these coupled dancers came together when the music started and continued in a fluid motion next to each other without bumping into each other or stepping on each other's toes.
Vela X-ray
Chandra X-ray telescope image of the Vela supernova remnant shows dramatic bow-like structures produced by the interaction of radiation and electron beams coming from the rapidly rotating neutron star in its center.

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Angle-resolved photoemission spectroscopy (ARPES) is a direct experimental technique to observe the distribution of the electrons (more precisely, the density of single-particle electronic excitations) in the reciprocal space of solids.
BCS Quasiparticle Formation
An illustration of the process by which a BCS quasiparticle becomes a mixture of a normal state quasiparticle and quasihole and in so doing acquires an energy gap.
Cuprate Superconductors
A candidate phase diagram based, in part, on magnetic measurements of normal state behavior, for the cuprate superconductors.
Effective Interaction
The net effective interaction between electrons in a metal.
Electronic Band Structure
Comparison of the electronic band structures of metals, semiconductors, and insulators.
Fermi Surface with Holes and Electrons
The Fermi surface reveals how the energy varies with momentum for the highest-energy electrons—those that have the Fermi energy.
Helium Phases
Temperature-pressure phase diagrams of the two quantum materials, 3He and 4He, that remain liquid down to the lowest temperatures in the absence of pressure compared to a typical liquid-solid phase diagram.
INS and Phonon Spectrum
Top: Experimental set-up for measurement of energy loss spectrum of neutrons that are inelastically scattered by a crystal. Bottom: A typical phonon spectrum obtained through an elastic neutron scattering (INS) experiment.
Kondo Lattice Scaling Behavior
A candidate phase diagram for CeRhIn5 depicting the changes in its emergent behavior and ordering temperatures as a function of pressure.
Magnetic Interaction
Magnetic interaction potential in a lattice.
Magnetic Quasiparticle Interaction
The magnetic quasiparticle interaction between spins s and s'.
Neutron Star Cross-Section
A cross section of a neutron star shows the rich variety of emergent quantum matter expected in its crust and core.
An illustration of two possible regimes of pinning for superfluid vortices in the crust of a neutron star.
Illustration of the temperature evolution of the Fermi surface in underdoped cuprates.
As shown in the figure, dimensionality can influence dramatically the behavior of quasiparticles in metals.
Superconducting SQUID
A Superconducting Qantum Interference Device (SQUID) is the most sensitive type of detector of magnetic fields known to science.
Superfluid Vortex
Geometry of a straight vortex line in a superfluid.
Two Types of Superconductors
Left: conventional superconductors, and right: heavy-electron superconductors.
Vela Pulsar
Radiotelescope observations of glitches and postglitch behavior in the Vela pulsar.