NMR relaxation rate in metallic carbon nanotubes Original Research Article

Magnetic properties of spin systems on the two-leg ladder made of organic radicals are studied. The magnetization measurements below 4.2 K in pulsed magnet fields up to about 50 T were done for BIP-BNO as an S=1/2 ladder and for BIP-TENO as an S=1 ladder. An energy gap above the singlet ground state is observed for each compound. Experimental results of magnetizations and susceptibilities are understood from the analysis using the results of the numerical diagonalizations.