Signal-based classical emulation of a universal quantum computer

TL;DR

This paper introduces a classical signal-based method to emulate a universal quantum computer, using analog electronic circuits to perform quantum gate operations, with potential advantages in robustness and ease of construction.

Contribution

The paper presents a novel classical emulation of quantum computing using signals and analog circuits, enabling full quantum state and gate operation simulation.

Findings

Emulation uses signals of bounded duration and amplitude.

Scalability limited by exponential bandwidth growth.

Potential for robustness and efficiency comparable to high-performance computers.

Abstract

In this paper we present a novel approach to emulating a universal quantum computer with a classical system, one that uses a signal of bounded duration and amplitude to represent an arbitrary quantum state. The signal may be of any modality (e.g., acoustic, electromagnetic, etc), but we focus our discussion here on electronic signals. Unitary gate operations are performed using analog electronic circuit devices, such as four-quadrant multipliers, operational amplifiers, and analog filters, although non-unitary operations may be performed as well. In this manner, the Hilbert space structure of the quantum state, as well as a universal set of gate operations, may be fully emulated classically. The required bandwidth scales exponentially with the number of qubits, however, thereby limiting the scalability of the approach, but the intrinsic parallelism, ease of construction, and classical robustness to decoherence may nevertheless lead to capabilities and efficiencies rivaling that of current high performance computers.