48 research outputs found
Finding Traps in Non-linear Spin Arrays
Precise knowledge of the Hamiltonian of a system is a key to many of its
applications. Tasks such state transfer or quantum computation have been well
studied with a linear chain, but hardly with systems, which do not possess a
linear structure. While this difference does not disturb the end-to-end
dynamics of a single excitation, the evolution is significantly changed in
other subspaces. Here we quantify the difference between a linear chain and a
pseudo-chain, which have more than one spin at some site (block). We show how
to estimate a number of all spins in the system and the intra-block coupling
constants. We also suggest how it is possible to eliminate excitations trapped
in such blocks, which may disturb the state transfer. Importantly, one uses
only at-ends data and needs to be able to put the system to either the
maximally magnetized or the maximally mixed state. This can obtained by
controlling a global decoherence parameter, such as temperature.Comment: 5 pages, 1 figur
Translating Concepts of State Transfer to Spin-1 Chains
State transfer is a well-known routine for various systems of
spins-. Still, it is not well studied for chains of spins of larger
magnitudes. In this contribution we argue that while perfect state transfer may
seem unnatural in spin-1 systems, it is still feasible for arrays of V-type
three-level atoms. Tomography of such 1D array is also shown to be possible by
acting on one atom from such an array