100 T Science
Neil Harrison – Capability Leader
Description of Capabilities
Magnetic fields are a key tuning parameter in experimental sciences, particularly in condensed matter physics. In metals, magnetic fields confine electrons to undergo circular motion. The size of the orbiting electrons paths is reduced as the magnetic field strength increases, collapsing to length scales of order a nanometer once the magnetic field intensity reaches 100 T. This dimensional collapse has profound affects on the quantum properties of the metal, leading to new physical observations enabling a deeper insight into the correlations between electrons.
Strong magnetic fields have some of the most profound consequences in systems where electrons are bound in pairs, such as in the case of a superconductor. Strong magnetic fields can break apart the pairs, uncovering the physical properties of the individual electrons from which the pairs are formed. In high temperature superconductors such binding is unusually strong, requiring fields of up to 100 T, and in some cases more. Experiments performed at Los Alamos in fields approaching 100 T have enabled some of the first measurements of the microscopic quantum properties of the normal electrons to be made in high temperature superconductors (see figure below), fundamentally changing our understanding of the role of strong correlations between electrons.
Strong magnetic fields also alter the properties of systems consisting of bound electron-hole pairs, such as in the case of an excitonic insulator, or paired spins, as in quantum magnets. In these systems, magnetic fields couple primarily to the electron spin rather than their orbital motion. Such coupling can yield new types of excitation or, possibly, entirely new magnetic field-induced phases.
For more information, contact Neil Harrison.
Example of magnetic quantum oscillations in the high temperature superconductor YBa2Cu3O6+x, in which the superconducting pairs are broken by a magnetic field enabling access to the quantum properties of the normal electrons (Published in PNAS, 2010.)
National High Magnetic Field Laboratory/NHMFL
Low Energy Spectroscopy