Abstract: Preservation of quantum entanglement in a two-qubit system is achieved by use of the disclosed systems. Three different example two-qubit systems are shown: (1) a system employing a weak measurement, (2) a system in which a generalized amplitude dampening occurs without use of a weak measurement, and (3) an extended system in which the system is prepared in a more robust state less susceptible to decoherence prior to a generalized amplitude dampening.

Abstract: According to one embodiment of the present invention, identifying a molecule of a sample includes illuminating the sample with a preparation light beam, where the preparation light beam can initiate a substantially maximized coherence of a target molecule to yield a molecular signature corresponding to the target molecule. The sample is illuminated with a probe light beam, where the probe light beam can scatter radiation from the sample. Radiation scattered from the sample is detected, and whether the radiation exhibits the molecular signature is determined. The target molecule is identified in accordance with the determination of whether the radiation exhibits the molecular signature.