The layered insulator a-RuCl3 is currently the best proximate to the Kitaev honeycomb Hamiltonian. Below 7 K it enters an antiferromagnetic zig-zag phase. However, application of an in-plane magnetic field B || the zigzag axis a suppresses the zigzag order. In the field interval 7 to 11.5 T, the system is widely believed to be in a quantum spin liquid state (QSL). I will report on experiments measuring Kxx and Kxy in the QSL state at temperatures down to 0.4 K.