Engineered Decoherence: Characterization and Suppression

Abstract

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.

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Cited by in corpus (4)

• Experimental demonstration of selective quantum process tomography on an NMR quantum information processor
• Controlling NMR spin systems for quantum computation
• Spectral investigation of the noise influencing multi-qubit states
• Irreversible decoherence of dipole interacting nuclear spins coupled with a phonon bath