Time: 3:30 PM, Fri, Feb. 24
Place: Sumwalt 120A (Nanocenter, small conference room)

Speaker: Dr. V.R. Shaginyan
(Petersburg Nuclear Physics Institute, Gatchina 188300 Russia)

Title: Discovering Strongly Correlated Spin Liquid

In the insulator herbertsmithite ZnCu3(OH)6Cl2, an exotic quantum spin
liquid (QSL) is formed with such hypothetic particles as fermionic spinons
carrying spin 1/2  and no charge. We analyze the thermodynamic and
relaxation properties, and unveil the fundamental properties of QSL,
forming strongly correlated Fermi system. The key features of our findings
are the presence of spin-charge separation and QSL formed with itinerant
spinons in herbertsmithite.  Herbertsmithite represents a fascinating
experimental example of a new strongly correlated insulator when new
particles-spinons, non-existing as free ones, dominate its properties at
low temperatures.  As a result, the low-temperature thermodynamic, heat
transport and relaxation properties of herbertsmithite are similar to
those of metals rather than of insulators.

[1] V. R. Shaginyan, A. Z. Msezane, and K. G. Popov,
Thermodynamic properties of the kagome lattice in herbertsmithite,
Phys. Rev. B 84, 060401(R) (2011).