Fig. 2: Dimensionality and dynamics from many-body noise.
From: Probing many-body dynamics in a two-dimensional dipolar spin ensemble
a, The normalized coherence for a DEER measurement on sample S1 (blue) and sample S2 (yellow) as a function of the free evolution time t. Dashed blue lines indicate the predicted early- and late-time stretch powers of 2/3 and 1/3, respectively, for a dipolar spin system in two dimensions. The dashed yellow line depicts the predicted early-time stretch power of 1 for a dipolar spin system in three dimensions (Table 1). Together, these data demonstrate the two- and three-dimensional nature of samples S1 and S2, respectively. The lower right insets show the same data on a linear scale. The top left inset shows the DEER pulse sequence. b, Spin echo measurements on three-dimensional dipolar spin ensembles in samples S3 (teal) and S4 (red) clearly exhibit a stretch power of 3/2 (dotted lines) over nearly two decades in time. This is consistent with the presence of Gaussian noise and allows one to explicitly rule out telegraph noise. The lower right inset shows the same data on a linear scale. The top left inset shows the spin echo pulse sequence. All data are presented as mean ± s.e.m.
