Coupling strength estimation for spin chains despite restricted access
Daniel Klaus Burgarth, Koji Maruyama, Franco Nori · Physical Review A · 2009
Quantum control requires full knowledge of the system many-body Hamiltonian. In many cases this information is not directly available due to restricted access to the system. Here we show how to indirectly estimate all the coupling strengths in a spin chain by measuring one spin at the end of the chain. We also discuss the efficiency of this ``quantum inverse problem'' and give a numerical example.