A two spin interferometer and the ESR STM phenomenon

We demonstrate a novel method for detecting spin resonance by an STM current noise The current passes in parallel via two localized spin states with g factors g1 g2 respectively We show theoretically that in presence of spin orbit coupling strong signals appear at both high and low frequencies g1 g2 H as well as weaker signals at g1 H g2 H where H is the magnetic field We have measured such signals with one spin on a Tempo molecule while the other spin is possibly on the Pt Ir tip in good agreement with the theoretical model We have also measured consistent low frequency signals on SiC films using magnetic field modulation Experimental work is with Y Manassen s group