In my previous question I asked who invented a quantum computer using qubits.
As a follow-up to this question I want to ask who built the first quantum computer using at least two qubits.
During my research I have discovered that in 1998, Jonathan A. Jones and Michele Mosca developed a quantum computer using two qubits specifically to solve Deutsch's problem. Have there been other working quantum computers before to solve other problems or general attempts not specifically bound to one problem?