Abstract

Many applications and experiments consists of the ensemble of the two-level systems (TLS) and the electro-magnetic (EM) field to control the quantum state of TLS. In such situations, the ability to precisely control the population and phase of TLS plays crucial role in many applications like nuclear magnetic resonance spectroscopy and imaging (NMR), quantum computer, atomic clocks, and magnetometer. Dephasing degrades the quality of the control mentioned above. For example, in Ramsey spectroscopy, making the free precession time to be too long leads to degrading the quality of the Ramsey fringes, due to the dephasing.