What was the first quantum computer?
Maryland researchers program a five-qubit trapped-ion computer
Most quantum experiments until then had been arranged for a single purpose: the pulses, their timing and the hardware were set up to run one particular algorithm, and running another meant reworking much of the setup.
In August 2016 a team at the University of Maryland led by Christopher Monroe, who had helped demonstrate the first quantum logic gate at NIST in 1995, reported a different approach.
Their machine held five trapped ions, each a qubit. Software translated an algorithm into a sequence of operations native to the hardware, so the same device could run different calculations without being altered. The team ran several: the Deutsch–Jozsa and Bernstein–Vazirani algorithms, and a quantum Fourier transform, the step at the heart of Shor's algorithm.
In the terms Deutsch had used in 1985, this was a machine that could be programmed rather than rebuilt. The paper's title called it a small programmable quantum computer.
five-qubit trapped-ion quantum computer that can be programmed in software to implement arbitrary quantum algorithmsNature