Abstract: Detection and recognition of taggant substances having predefined zero external field magnetic resonance signatures. An object comprising taggant substance(s) is irradiated with a sequence of specific excitation pulses of electromagnetic radiation within a predetermined time and frequency scanning pattern, responsive nuclear spin echo signals are received from the object with a predetermined time and frequency acquisition pattern and data indicative thereof is generated. The scanning and acquisition patterns used permit successive transmission of pulses of multiple frequencies using a two-pulse spin-echo excitation technique, or a steady state-spin echo excitation technique, and successive acquisition of multiple nuclear spin echo response signals, within a time slot between two successive excitation pulses of a specific excitation frequency.

Abstract: A method of labeling, authenticating and/or identifying a paper, credit/identification card, bank note, article or any other object using both nuclear magnetic resonance in magnetically ordered materials and nuclear quardrupole resonance phenomena as well as other phenomena of electric/magnetic dipole or tunnel transitions between Stark-Zeeman sub-levels, frequencies of which belong to the radio-frequency band. A minor amount of at least one authenticating substance is added to the object, the substance having a strong unique and identifiable response in radio-frequency domain at room temperature, with the spectroscopy being performed in the absence of any supported external static field, and with any specific response (intensity, line width, line shape, splittings, free induction decay, spin echoes or their combinations) being used as a criterion for discrimination.