  Due to omnipresent environmental interferences, quantum coherences inevitably
undergo irreversible transformations over certain time-scales, thus leading to
the loss of encoded information. This process, known as decoherence, has been a
major obstacle in realizing efficient quantum information processors.
Understanding the mechanism of decoherence is crucial in developing tools to
inhibit it. Here we utilize a method proposed by Cory and co-workers [Phys.
Rev. A 67, 062316 (2003)] to engineer artificial decoherence in the system
qubits by randomly perturbing their surrounding ancilla qubits. Using a two
qubit nuclear magnetic resonance quantum register, we characterize the
artificial decoherence by noise spectroscopy and quantum process tomography.
Further, we study the efficacy of dynamical decoupling sequences in suppressing
the artificial decoherence. Here we describe the experimental results and their
comparisons with theoretical simulations.
