By Will Soutter
Physicists at the National Institute of Standards and Technology (NIST) have succeeded in achieving controlled acceleration of beryllium ions and bringing them to a stop in a timeframe of few microseconds.
The unique aspect of this experiment is not just in the ions coming to a complete stop after acceleration but in the ability of the ions to regain their original energy state after coming to a stop. The physicists consider these fast moving ions to be potential candidates for future quantum computers.
During the experiment, the ions were found to travel at a speed of 100 miles/hr, covering 370 mµ of an ion trap in 8 µs . This is 100 times faster than what has been possible previously. Though ions can move really fast in accelerators, such precision controlled movements and stops without any effect on the electron energy levels make the results of this study significant for quantum computing which requires information carried around by these ions to be kept intact. If ions were to be used to carry information in the form of quantum bits or qubits within the quantum processor, the transport of ions can be implemented physically as opposed to existing method of performing logical operations on the ions.
Since the new technique to move ions is equivalent in duration to the logical operation, employing the new technique will decrease processing overhead and will facilitate quicker reuse of ions. The team at NIST employed custom electronics to achieve controlled speed. They used fast FPGA (field programmable gate array) devices to regulate the input voltage and duration for which the voltage was applied across electrodes in the ion trap. This served to accelerate the ions without exciting them to very high energy levels.