Physicists Uncover Novel Phase of Matter (phys.org)

schwit1 writes: A team of physicists led by Caltech's David Hsieh has discovered an unusual form of matter — not a conventional metal, insulator, or magnet, for example, but something entirely different (abstract). This phase, characterized by an unusual ordering of electrons, offers possibilities for new electronic device functionalities and could hold the solution to a long-standing mystery in condensed matter physics having to do with high-temperature superconductivity — the ability for some materials to conduct electricity without resistance, even at "high" temperatures approaching -100 degrees Celsius. "The discovery of this phase was completely unexpected and not based on any prior theoretical prediction... The whole field of electronic materials is driven by the discovery of new phases, which provide the playgrounds in which to search for new macroscopic physical properties."

Comments

Re: Do you expect...

[Anonymous Coward]

You and the mods are several decades out of date. Phases of matter are no longer about one of the four classic categories you listed, but about thermodynamic transitions. Materials that transition from insulator to conductor in certain ways are undergoing a phase transition, as are changes in magnetic properties. This makes things like insulator and ferromagnetism a phase of matter in some cases, which undergoes a phase transition in response to temperature, magnetic field, or other external controls.

For some reason, most education on thermal and statistical mechanics stops about the 1870s, and doesn't cover more interesting physics, like the statistical definition of temperature instead of the kinetix (they overlap, the former is a superset of the latter).

click bait title is misleading...

[morethanapapercert]

This is probably a Slashdot problems sort of thing. But for me, just the bare title of the actual paper being referred to is more informative and easier to comprehend than the journalist written popularization of it...

Evidence of an odd-parity hidden order in a spin–orbit coupled correlated iridate

Re:Nice bit of spin (pun intended)

[slew]

"The discovery of this phase was completely unexpected and not based on any prior theoretical prediction"

and yet for some reason they decided to build a detector specifically to look for these arrangements of electrons....

Actually, I think the original use of the detector was to developed a faster way to determine structure of crystal/electronic symmetries in solids (by measuring high-order non-linear harmonics and inferring the structure, not specifically looking for a particular arrangement). The interesting thing about this detector is that it doesn't involve moving the sample under test, so you can test samples that are under conditions that would be otherwise impractical to test using other techniques.

This latest result using this detector on Sr2IrO4 yielded a measurement that indicated a structure that didn't match the expected underlying crystal structure (thus unexpected). Furthermore, the presence of this unrelated structure seemed to be temperature dependent indicating a possible novel phase of matter that formed at a critical temperature.

Using optical second-harmonic generation, we report evidence of a hidden non-dipolar magnetic order in Sr2IrO4 that breaks both the spatial inversion and rotational symmetries of the underlying tetragonal lattice. Four distinct domain types corresponding to discrete 90-rotated orientations of a pseudovector order parameter are identified using nonlinear optical microscopy, which is expected from an electronic phase that possesses the symmetries of a magneto-electric loop-current order.