Seminarium Fizyki Materii Skondensowanej

An electron spin localized in a semiconductor is coupled by contacthyperfine interaction to the nuclei of the atoms of the host material. Thiscoupling is the main reason for decoherence of semiconductor-based spinqubits. Describing the process of decoherence is an interesting problem,because the experimentally relevant parameter regime corresponds to strongqubit-bath coupling, and the bath dynamics is very slow. Both of thesefeatures preclude the use of Born-Markov approximation commonly used fordescription of open quantum systems. I will try to give a survey oftheoretical methods which were used (with varying degree of success) toattack this problem during the last 10 years.