noisy environment that induces a non-exponential decay [@PhysRevA.84.012103; @chin2012quantum; @tanaka2015proposed; @RevModPhys.88.021002].

In this work, we investigate the behavior of the entangled sensor in engineered noisy environment with NMR. Since the performance of the entangled sensor strongly depends on the properties of the environment, systematic experimental analysis of the entangled sensor with various type of noise is essential for the realization of the quantum enhanced sensing. So our experimental investigation with NMR model would provide insight to assess the practicality of quantum sensors.

The rest of the paper is organized as follows. In Sect. 2, we closely follow Refs. [@Jones1166; @PhysRevA.82.022330] and review how the entangled sensor is simulated with a star topology molecule. We then present the method how to prepare an engineered noisy environment following Ref. [@Binho2019]. Then, these two ideas are combined: we simulate the entangled sensor under the presence of an engineered noisy environment. We show experimental results in Sect. 3, where a dynamics of the entangled sensor in a time-inhomogeneous noisy environment and a successful application of a dynamical decoupling technique [@RevModPhys.88.041001] to the entangled sensor are shown. The last Sect. 4 is devoted to summary.

Theory
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In this section, we describe our strategy to 