Universal Nonadiabatic Geometric Gates in Two-Qubit Decoherence-Free Subspaces

Geometric quantum computation in decoherence-free subspaces is of great practical importance because it can protect quantum information from both control errors and collective dephasing. However, previous proposed schemes have either states leakage or four-body interactions problems. Here, we propose a feasible scheme without these two problems. Our scheme is realized in two-qubit decoherence-free subspaces. Since the Hamiltonian we use is generic, our scheme looks promising to be demonstrated experimentally in different systems, including superconducting charge qubits.