The tunable quantum spin ladder Cu(Qnx)(Cl${}_{(1-x)}$Br${}_x$)${}_2$

K. Yu. Povarov, W. E. A. Lorenz, F. Xiao +3

We report magnetic, specific heat and ESR measurements on a series of $S=1/2$ spin ladder compounds Cu(Qnx)(Cl${}_{(1-x)}$Br${}_x$)${}_2$. Down to $T=2$ K all the observables can be…