Browse Visuals

By Unit:
1. The Basic Building Blocks of Matter
2. The Fundamental Interactions
3. Gravity
4. String Theory and Extra Dimensions
5. The Quantum World
6. Macroscopic Quantum Mechanics
7. Manipulating Light
8. The Challenges of Complexity
9. Biophysics
10. Dark Matter
11. Dark Energy

Visuals: Unit 6

Animations

BCS Pairs: The stronger the attraction between pairs, the greater the resistance of the pairs to breaking apart.

Behavior of Bosons and Fermions: The quantum mechanical behavior of bosons is always to do the same thing. The quantum mechanical behavior of fermions is never to do the same thing.

Bosons to BEC: When a gas of bosons is cooled to an extremely low temperature, bosons create a new state of matter—a Bose-Einstein Condensate or BEC.

Cooling a Gas of Fermions: A gas of fermions is cooled and the motion of the atoms in a trap is quantized. There is quite a bit of kinetic energy in that gas even at low temperatures.

Cooper Pairing: Unlike Jin's initial Fermi condensate, there is a different kind of pairing involved with superconductors called "cooper pairing."

Cooper Pairing and Superconductivity: One electron moving in one direction and one electron moving in the opposite direction somehow move in some correlated way.

From Fermions to BEC: In Jin's achievement of a Fermi condensate, the key breakthrough was coercing individual fermionic atoms to pair together creating bosonic molecules.

Scanning Tunneling Microscope: An electric voltage is applied between the microscope tip and the sample. Measuring the current can reveal quantum mechanical features of the sample.

Standard vs. Super Conductors: In a typical copper cable, there's resistance. In a superconductor, when you send electrons in one end, they come out the other end with no energy loss.

Superconductor Properties: Superconductors are materials with two essential properties: They have zero resistance and expel magnetic fields.

Superfluid Fountain: A fountain of superfluid ⁴He.

Timeline of Type I and Type II Superconductors: The first (Type I) superconductors were cooled at least to 30 Kelvin. In 1986, a new class of high-temperature superconductors (Type II) was found.

Type I and Type II Superconductors: Type I superconductors expel the magnetic field uniformly. Type II allow the magnetic field to penetrate in quantized packets called "vortices."

Vortices: Unpinned vortices can move, forming a regular pattern in the STM images. Pinned vortices are scattered irregularly throughout the image.

Photographs

BEC Vortices: The formation of vortices in this BEC shows that it is a superfluid.

Cotton Ball Model: A cotton ball model of an atom.

Magnetic Resonance Imaging: Superconducting magnets enable MRI machines to produce dramatic images.

Mendeleev and Lewis: The father and son of chemical periodicity: Dmitri Mendeleev and Gilbert Newton Lewis.

Plum Pudding Model: Plum pudding (or raisin scone) model of the atom.

Stern-Gerlach Experiment: The Stern-Gerlach experiment demonstrated that spin is quantized.

Graphics

BEC Oscillations: Super-oscillations of a quantum gas and their dissipation on heating.

Blackbody Spectra: The spectrum of blackbody radiation at different temperatures.

Bose Condensate: Atoms in a Bose condensate at 0 K.

Bose-Einstein Condensation: Some of the first experimental evidence for a gaseous macroscopic quantum state.

Bose-Einstein Condensation: Three stages of cooling, and a quantum phase transition to a BEC.

Bosons and Fermions: Atoms in a trap at 0 K: bosons form a BEC (left) and fermions form a degenerate Fermi gas (right).

Complex Quantum Wave: While the complex part of a quantum wavefunction "waves," the probability density does not.

Composite Fermions and Bosons: Protons in LHC collisions (left) and electrons in a superconductor (right) are examples of composite fermions and bosons.

Diffraction in Random Media: Diffraction of green laser light passing though a random medium.

Early Periodic Table: An early version of Mendeleev's Periodic Table, showing the positions of missing elements.

Ground State of Helium: The ground state of helium: energy levels and electron probability distribution.

Helium Isotopes: The two isotopes of helium: a fermion and a boson.

Interfering Bose-Einstein Condensates: Interference of two coherent BECs, separated and allowed to recombine.

Lewis Shell Model: The Lewis shell model for the first three atoms in the modern periodic table.

Li, Na, and K Energy Levels: Electrons in atomic energy levels for Li, Na, and K.

Molecular BEC interference: Interference pattern created by the overlap of two clouds of molecular BECs, each composed of ⁶Li₂ diatomic molecules.

Multiwavelength Milky Way: Our galaxy, imaged at many different wavelengths.

Nuclides: As this chart shows, not every imaginable nucleus is stable.

Oscillating Model of Helium Atom: A simple classical model fails to explain the stability of the helium atom.

Quantum Vortices: Quantum vortices in a BEC (top) and the corresponding phase of the quantum wavefunction (bottom).

Rutherford's Hydrogen Atom: Rutherford's model of a hydrogen atom.

Shell Model for Molecules: Molecules in the Lewis shell picture: the pair bond for H₂ and Li₂.

Soliton: Density notch soliton.

Spin Pairing in Molecules: Spin pairing in the molecules H₂ and Li₂.

Temperature and the de Broglie Wavelength: Atomic de Broglie waves overlap as temperatures are lowered.