Abstract: We investigate the decoherence patterns of topological qubits in contact with the environment by a novel way of deriving the open system dynamics other than the Feynman-Vernon. Each topological qubit is made of two Majorana modes of a 1D Kitaev's chain. These two Majorana modes interact with the environment in an incoherent way which yields peculiar decoherence patterns of the topological qubit. More specifically, we consider the open system dynamics of the topological qubits which are weakly coupled to the fermionic/bosonic Ohmic-like environments. We find that the topological qubits decohere completely in the Ohmic and sub-Ohmic environments but not in the super-Ohmic ones. This is in contrast to the cases of non-topological qubits for which they always decohere completely in all Ohmic-like environments unless the probe-environment is strong enough.  

 

About the Speaker: Feng-Li Lin received his B.Eng. degree (1988) in Electrical Engineering from National Sun-Yat-Sen University and M.S. degree (1990) in Physics from National Tsing-Hua University, and his Ph.D. degree (2000) in Physics from the University of Utah. After postdoctoral positions at the Seoul National University (2000-2001), Tamkang University (2001-2002) and National Center for Theoretical Sciences (2002-2004) in Taiwan, he joined the National Taiwan Normal University as an assistant professor (2004) and then got promoted to associate professor (2007) and full professor (2010). In 2012 he spent a year of research on-leave as a visiting professor at Department of Physics, Massachusetts Institute of Technology. Currently he is appointed as the Center Scientist of National Center for Theoretical Sciences. Prof. Lin’s research covers many topics in theoretical sciences, including string theory, black hole physics, quantum information sciences and strongly correlated condensed matter systems. Recently, he is interested in the inter-disciplinary study of the related topics on quantum entanglement.