Quantum register of fermion pairs

Pairing of fermions lends stability and robustness to matter, from nuclei and atoms to superconductors and neutron stars. In this talk, we demonstrate the use of fermion pairs in an optical lattice for robust encoding and manipulation of quantum information. With each fermion pair forming a spin singlet, the qubit is realized as a set of degenerate, symmetry-protected, two-particle vibrational wavefunctions. Degeneracy is lifted by the atomic recoil energy of the optical lattice, rendering two-fermion motional qubits insensitive against noise in the confining potential. Our method provides a new route toward quantum computation and simulation by leveraging Pauli exclusion for high fidelity preparation and control of entangled motional states of fermions.