Two-dimensional transport and transfer of a single atomic qubit in optical tweezers

Quantum computers have the capability of out-performing their classical counterparts for certain computational problems(1). Several scalable quantum-computing architectures have been proposed. An attractive architecture is a large set of physically independent qubits arranged in three spatial regions where ( 1) the initialized qubits are stored in a register, ( 2) two qubits are brought together to realize a gate and ( 3) the readout of the qubits is carried out(2,3). For a neutral-atom-based architecture, a natural way to connect these regions is to use optical tweezers to move qubits within the system. In this letter we demonstrate the coherent transport of a qubit, encoded on an atom trapped in a submicrometre tweezer, over a distance typical of the separation between atoms in an array of optical traps(4-6). Furthermore, we transfer a qubit between two tweezers, and show that this manipulation also preserves the coherence of the qubit.