Fidelity of sequences of SWAP operations in chains of multiple coupled qubits*

We investigate the swapping of qubit states between neighboring qubits in a chain of multiple qubits with quasistatic noise both in the (nearest-neighbor) couplings between them and in fields applied to the individual qubits. We will assume no intentionally applied fields, so that all such fields that appear are due entirely to noise. We consider chains of several different lengths and different sequences of SWAP operations (i.e., different pairs of neighboring qubits to perform the operation on and different lengths). We determine the fidelity of these sequences as a function of sequence and qubit chain length for different noise strengths.