Quantum random access memory

TL;DR

This paper introduces a quantum RAM architecture that significantly reduces the complexity and power requirements for quantum memory access, enabling more efficient quantum computing applications.

Contribution

The authors propose an architecture for qRAM that exponentially decreases the number of switches and entanglement needed compared to traditional designs.

Findings

Exponential reduction in switches required for memory access

More robust qRAM algorithm with less entanglement

Potential for lower power consumption in quantum memory addressing

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.