High-energy states of matter

Plasma (ionized gas)
Main article: Plasma (physics)
Plasmas or ionized gases can exist at temperatures starting at several thousand degrees C. Two examples of plasma are the charged air produced by lightning, and a star such as our own sun.
As a gas is heated, electrons begin to leave the atoms, resulting in the presence of free electrons, which are not bound to an atom or molecule, and ions, which are chemical species that contain unequal number of electrons and protons, and therefore possess an electrical charge. The free electric charges make the plasma electrically conductive so that it responds strongly to electromagnetic fields. At very high temperatures, such as those present in stars, it is assumed that essentially all electrons are "free," and that a very high-energy plasma is essentially bare nuclei swimming in a sea of electrons. Plasma is believed to be the most common state of matter in the universe.
A plasma can be considered as a gas of highly ionized particles, but the powerful interionic forces lead to distinctly different properties, so that it is usually considered as a different phase or state of matter.
Quark-gluon plasma
Main article: Quark-gluon plasma
This is a state of matter discovered at the CERN in 2000, in which the quarks that would normally make up protons and neutrons are freed and can be observed individually, similar to splitting molecules into atoms. This state of matter allows scientists to observe the properties of individual quarks, and not just theorize.
Other proposed states
Main article: List of states of matter
Degenerate matter
Main article: Degenerate matter
Under extremely high pressure, ordinary matter undergoes a transition to a series of exotic states of matter collectively known as degenerate matter. These are of great interest to astrophysics, because these high-pressure conditions are believed to exist inside stars that have used up their nuclear fusion "fuel", such as white dwarves and neutron stars.
Supersolid
Main article: Supersolid
A supersolid is a spatially ordered material (that is, a solid or crystal) with superfluid properties. A supersolid is a solid, but exhibits so many other properties that many argue it is another state of matter
String-net liquid
When in a normal solid state, the atoms of matter align themselves in a grid pattern, so that the spin of any electron is the opposite of the spin of all electrons touching it. But in a string-net liquid, atoms are arranged in some pattern which would require some electrons to have neighbors with the same spin. This gives rise to some curious properties, as well as supporting some unusual proposals about the fundamental conditions of the universe itself.
Superglass
Main article: Superglass
A superglass is a phase of matter which is characterized at the same time by superfluidity and a frozen amorphous structure.