A new kind of magnetic resonance observed in the organic molecular metal alpha-(BEDT-TTF)(2)KHg(SCN)(4)

We experimentally demonstrate a mechanism for a new kind of magnetic resona nce, the Fermi-surface traversal resonance (FTR). This is caused by the per iodic traversal of carriers across quasi-one-dimensional (Q1D) sections of Fermi surface (FS) in an external magnetic field. Owing to the warping of t he Q1D Fermi sheets, the real space velocities of the carriers oscillate as they cross the FS, generating resonances in the high frequency conductivit y of the material. The results contain information about the FS, including the direction and harmonic content of the warping components. Using a rotat ing resonant-cavity system, FTRs have been observed in alpha-(BEDT-TTF)(2)K Hg(SCN)(4). (C) 1998 Elsevier Science B.V. All rights reserved.