No abstract

Rabi oscillations are known to exhibit non-Bloch behaviour in anisotropic media. In this letter, we report an experimental observation of non-Bloch decay of Rabi oscillations in isotropic liquid state NMR. To avoid the dephasing due to the radio-frequency inhomogeneities, we develop a modified version of the rotary echo protocol and use it to determine the decay rates of Rabi oscillations. We find that the measured decay rates are proportional to the square of the Rabi frequencies and the proportionality constant is of the order of tens of picoseconds. Further, we show that this non-Bloch nature of the decay rates becomes less prominent with increasing temperature. The implications of the presence of non-Bloch decay rates in liquid state NMR in the context of ensemble quantum computing are also discussed.

No abstract

Recently, a sequence with a set of non-equidistant π pulses, often referred to as Uhrig's Dynamic Decoupling (UDD) sequence has been proposed which is shown to be more efficient in suppressing the time dependent systematic sources of dephasing originating from a bosonic bath. This work aims to investigate the potential of such non-equidistant sequences for more accurate measurement of the transverse relaxation time (T2) in liquid state NMR. We have shown experimentally that the dynamic decoupling schemes can estimate T2 more accurately than the equidistant pulse sequence by suppressing the dephasing effects of the field noise in the solution state.