The quantum devices group has participated with theoretical support in a study of a new type of superconducting devices where the transmon qubit is extended with a quantum dot in one of the Josephson junctions. The research was carried out in collaboration with QuTech and Kavli Institute of Nanoscience at Delft University of Technology (Netherlands), Center for Quantum Devices, Niels Bohr Institute at the University of Copenhagen (Denmark), Leiden Institute of Physics at Leiden University (Netherlands), Institute of Materials Science in Madrid, CSIC (Spain), Dipartimento di Fisica, Università di Roma “La Sapienza” (Italy), and Department of Physics and Frederick Seitz Materials Research Laboratory, at University of Illinois Urbana-Champaign (USA). When there is one electron trapped in the quantum dot, the spin provides an additional degree of freedom. This results in a new type of qubit, Andreev spin qubit, which combines advantages of superconducting qubits and semiconductor spin qubits. The Ljubljana group contributed with numerical calculations of qubit Josephson potentials, theory of spin-flip tunneling terms resulting from spin-orbit coupling, and theory of impurity Knight shift.