A MEMS version of a legacy delay-line memory has been demonstrated as a viable scratchpad memory for future quantum computers by the National Institute of Standards and Technology (NIST, Boulder, Colorado).
The memory element in the MEMS (microelectromechanical system) resonates when hit with microwave pulses whose amplitude and phase encode the quantum information. Because the mechanical oscillations continue during the coherence time of a typical quantum operation, NIST believes the micron-sized memory could store temporary values during quantum calculations.
In principle, the MEMS memory performs like a legacy delay-line memory from early computer days, which stored scratchpad values in acoustic waves traveling down a column of mercury. In recent years, the same delay-line concept has been used in optical systems that measure out lengths of fiber cable to temporarily store information.
MEMS micro-drum and circuit on a sapphire backing. JILA researchers demonstrated that the drum might be used as a memory device in future quantum computers.
Image source: NIST
The current prototype has demonstrated 65 percent efficiency in temporarily storing quantum information, but NIST believes it can improve the data exchange between microwave photons, which excite the device, and the mechanical phonons, from which stored values are read out, making it a viable scratchpad memory for future quantum computers.
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