Perfect state transfer in a spin chain without mirror symmetry

Perfect state transfer in quantum spin networks.

We propose a class of qubit networks that admit the perfect state transfer of any quantum state in a fixed period of time. Unlike many other schemes for quantum computation and communication, these networks do not require qubit couplings to be switched on and off. When restricted to N-qubit spin networks of identical qubit couplings, we show that 2log3N is the maximal perfect communication dist...

Mirror symmetry without corrections

We give geometric explanations and proofs of various mirror symmetry conjectures for T-invariant Calabi-Yau manifolds when instanton corrections are absent. This uses fiberwise Fourier transformation together with base Legendre transformation. We discuss mirror transformations of (i) moduli spaces of complex structures and complexified symplectic structures, Hp,q’s, Yukawa couplings; (ii) sl (2...

Mirror Symmetry without Corrections

Perfect state transfer over distance-regular spin networks

By considering distance-regular graphs as spin networks, first we introduce some particular spin Hamiltonians which are extended version of those of Refs.[1, 2]. Then, by using spectral analysis techniques and algebraic combinatoric structure of distanceregular graphs such as stratification introduced in [3, 4] and Bose-Mesner algebra, we give a method for finding a set of coupling constants in...

Thermal effect and role of entanglement and coherence on excitation transfer in a spin chain

We analyze the role of bath temperature, coherence and entanglement on excitation transfer in a spin chain induced by the environment. In Markovian regime, we show that coherence and entanglement are very sensitive to bath temperature and vanish in time in contrary to the case of having zero-temperature bath. That is while, finding the last qubit of the chain in excited state increases by incre...