Uranium ruthenium silicide

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Uranium ruthenium silicide (URu₂Si₂) is a heavy fermion alloy composed of uranium, ruthenium, and silicon. URu₂Si₂ has the same '122' tetragonal crystal structure as many other compounds of present condensed matter research. URu₂Si₂ is a superconductor with a hastatic order (HO) phase below a temperature of 17.5 K.{{cite journal |author=H.-H. Kung1 |author2=R. E. Baumbach |author3=E. D. Bauer |author4=V. K. Thorsmølle |author5=W.-L. Zhang |author6=K. Haule |author7=J. A. Mydosh |author8=G. Blumberg |title=Chirality density wave of the "hidden order" phase in URu2Si2 |journal=Science |date=20 March 2015 |volume=347 | issue=6228 | pages=1339–1342 |doi=10.1126/science.1259729 |pmid=25678557 |arxiv=1410.6398 |bibcode=2015Sci...347.1339K |s2cid=30976070 }}{{cite journal |author=Premala Chandra|author-link=Premala Chandra |author2=Piers Coleman |author3=Rebecca Flint |title=Hastatic order in the heavy-fermion compound URu2Si2 |journal=Nature |date=31 January 2013 |volume=493 |issue=7434 | pages=621–626 |doi=10.1038/nature11820 |pmid=23364741 |arxiv=1207.4828 |bibcode=2013Natur.493..621C |s2cid=205232317 }} Below this temperature, it is magnetic, and below about 1.5 K it superconducts.{{cite book|first=Gernot | last=Goll |title=Unconventional Superconductors: Experimental Investigation of the Order-Parameter Symmetry | pages=107–111 |publisher=Springer| year=2006 |isbn=978-3-540-28985-2 |url=https://books.google.com/books?id=ISvIgVbxIs4C&pg=PA107}} However, the nature of the ordered phase below 17.5K is still under debate despite a wide variety of scenarios that have been proposed to explain this phase.