# Variational Quantum Eigensolvers in the Era of Distributed Quantum Computers

## TL;DR

This paper demonstrates that distributed quantum computing architectures with limited inter-module communication can effectively solve quantum problems, offering a promising approach for near-term modular quantum processors.

## Contribution

It introduces a variational quantum eigensolver tailored for a two-module architecture, showing that limited inter-module operations significantly enhance performance.

## Key findings

- Three inter-module operations outperform no inter-module communication.
- Distributed architectures can match monolithic performance with limited communication.
- Near-term modular quantum processors are viable alternatives to large monolithic systems.

## Abstract

The computational power of a quantum computer is limited by the number of qubits available for information processing. Increasing this number within a single device is difficult; it is widely accepted that distributed modular architectures are the solution to large scale quantum computing. The major challenge in implementing such architectures is the need to exchange quantum information between modules. In this work, we show that a distributed quantum computing architecture with {\it limited} capacity to exchange information between modules can accurately solve quantum computational problems. Using the example of a variational quantum eignesolver with an ansatz designed for a two-module (dual-core) architecture, we show that three inter-module operations provide a significant advantage over no inter-module (or serially executed) operations. These results provide a strong indication that near-term {\it modular} quantum processors can be an effective alternative to their monolithic counterparts.