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arXiv · 0708.1879

Quantum random access memory

Vittorio Giovannetti·Seth Lloyd·Lorenzo Maccone
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Abstract

A random access memory (RAM) uses n bits to randomly address N=2^n distinct memory cells. A quantum random access memory (qRAM) uses n qubits to address any quantum superposition of N memory cells. We present an architecture that exponentially reduces the requirements for a memory call: O(log N) switches need be thrown instead of the N used in conventional (classical or quantum) RAM designs. This yields a more robust qRAM algorithm, as it in general requires entanglement among exponentially less gates, and leads to an exponential decrease in the power needed for addressing. A quantum optical implementation is presented.

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Vittorio Giovannetti, Seth Lloyd, Lorenzo Maccone. 2008-03-26. Quantum random access memory. https://doi.org/10.1103/physrevlett.100.160501

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