Simulating decoherence behavior of a system in entangled state using   nuclear magnetic resonance
  By choosing H nucleus in Carbon-13 labelled trichloroethylene as one qubit environment, and two C nuclei as a two-qubit system, we have simulated quantum decoherence when the system lies in an entangled state using nuclear magnetic resonance (NMR). Decoupling technique is used to trace over the environment degrees of freedom. Experimental results show agreements with the theoretical predictions. Our experiment scheme can be generalized to the case that environment is composed of multiple qubits. 
Jingfu Zhang, Zhiheng Lu, Lu Shan, and Zhiwei Deng