What are ferroics and why do we study their physics?
Ferroic materials are the materials which have two or more orientational states of an order parameter in the absence of magnetic field, electric field, and mechanical stress and can shift from one to another of these states by means of one or combination of several external stimuli. In more simple words, examples of ferroics are:
- magnetically-ordered materials, in which one can switch magnetization back and forth;
- ferroelectrics, in which spontaneous polarization excists and can be switched back and forth;
- multiferroics, in which two or even more order parameters coexists, for example, magnetization and spontaneous polarization.
The role of ferroics in present technologies is enourmous. Just to mention: in HDD bits are stored in tiny volumes of a ferroic (magnetic) structure. Writing a bit means to switch a magnetization of one of these volumes. HAMR, MAMR, MRAM, FRAM and other emerging technologies are showing importance of ferroics and a request for improving devices built on base of them.
Changing a state of a ferroic material, i.e. switching an order parameter, exciting its dynamics, reversably destroying it - is an importnat technological challenge, and we need to find novel ways to manipulate properties of ferroics faster, more efficiently, and at a nanoscale. Can we use laser pulses - flashes of coherent light which last for just a few femtoseconds, to solve these problems? Or may be we need to find or contruct new ferroics, which would allow such ultrafast laser-induced manipulation of their properties.
We at Ferrolab, alone and in collaboration with colleagues from all over the world, are working on finding answers to at least some of these urgent questions.