<P> A quantum Hall state gives rise to quantized Hall voltage measured in the direction perpendicular to the current flow . A quantum spin Hall state is a theoretical phase that may pave the way for the development of electronic devices that dissipate less energy and generate less heat . This is a derivation of the Quantum Hall state of matter . </P> <P> Photonic matter is a phenomenon where photons interacting with a gas develop apparent mass, and can interact with each other, even forming photonic "molecules". The source of mass is the gas, which is massive . This is in contrast to photons moving in empty space, which have no rest mass, and cannot interact . </P> <P> A "quantum fog" of electrons and holes that flow around each other and even ripple like a liquid, rather than existing as discrete pairs . </P> <P> Under extremely high pressure, as in the cores of dead stars, ordinary matter undergoes a transition to a series of exotic states of matter collectively known as degenerate matter, which are supported mainly by quantum mechanical effects . In physics, "degenerate" refers to two states that have the same energy and are thus interchangeable . Degenerate matter is supported by the Pauli exclusion principle, which prevents two fermionic particles from occupying the same quantum state . Unlike regular plasma, degenerate plasma expands little when heated, because there are simply no momentum states left . Consequently, degenerate stars collapse into very high densities . More massive degenerate stars are smaller, because the gravitational force increases, but pressure does not increase proportionally . </P>

Three states of matter solid liquid and gas