Strongly correlated Fermi systems are among the most intriguing and fundamental systems in physics, whose realization in some compounds is still to be discovered. We show that ${\text{ZnCu}}_3{\left(\text{OH}\right)}_6{\text{Cl}}_2$ can be viewed as a strongly correlated Fermi system whose low-temperature thermodynamics in magnetic fields is defined by a Fermi quantum spin liquid. Our calculations of its thermodynamic properties are in good agreement with recent experimental facts and allow us to reveal their scaling behavior which strongly resembles that observed in heavy-fermion metals and two-dimensional ${}^3$He.

• Received 22 May 2011

DOI:https://doi.org/10.1103/PhysRevB.84.060401