  The low-temperature behavior of the magnetic insulator Cs2CuCl4 can be
modeled by an anisotropic triangular lattice spin-1/2 Heisenberg
antiferromagnet with two different exchange couplings J and J' = J/3. We show
that in a wide range of magnetic fields the experimentally observed field
dependence of the crossover temperature T_c for spin-liquid behavior can be
explained within a mean-field theory based on the representation of spin
operators in terms of Majorana fermions. We also show that for small magnetic
fields the specific heat and the spin susceptibility both exhibit a maximum as
a function of temperature at T_c = J/2. In the spin-liquid regime, the Majorana
fermions can only propagate along the direction of the strongest bond, in
agreement with the dimensional reduction scenario advanced by Balents [Nature
(London) 464, 199 (2010)].
