A quantum computer needs what is called a universal quantum gate, a device where the quantum state of one system changes depending on the state of another system. (discovermagazine.com)
While others have demonstrated this between two neutral atoms, they have not been able to retain quantum gates in systems involving large numbers of atoms. (sciencedaily.com)
Scientists have also shown that ions, under certain conditions, can be made to perform quantum gates — logical operations between two quantum bits, similar to logic gates in classical circuits. (sciencedaily.com)