Quantum dynamical neural networks

Introduction

Quantum neural networks are a young research field that has been rapidly expanding due to their potential to attain revolutionary computing capacities and the possibility to learn on quantum data, inaccessible to classical computers.

Current Limitations

However, despite impressive proof-of-concept results, currently existing approaches that rely on sparsely coupled qubits are not scalable to network sizes and connectivities with tunable weights required for state-of-the-art tasks.

Proposed Approach

In qDynnet, I will adopt a completely new and unexplored approach that uses parametrically coupled superconducting quantum oscillators instead of physically coupled qubits. This will allow me to obtain quantum neural networks of unprecedented size, connectivity, and tunability.

Implementation Strategy

To do this, I will shift the paradigm by implementing neurons as basis states of dynamically coupled multi-level quantum oscillators. Connections between neurons will be represented as transition rates obtained through different dynamical processes, such as:

1. Parametric coupling
2. Resonant drives
3. Dissipation

Experimental Goals

I will implement experimentally quantum neural network architectures that were only simulated until now and use them to demonstrate data classification with basis state neurons.

Advancing Complexity

In order to go towards more complex tasks, I will use parametric coupling to introduce tunable connections between neurons. I will develop new training methods that will allow me to tune connections in such dynamical quantum neural networks and use them to demonstrate learning to recognize quantum states.

Scalability and Impact

I will develop circuit geometries that will be scalable to large quantum neural networks with millions of neurons and tunable connections. The qDynnet project will provide understanding of physics and methods for dynamical coupling and training, which will have a broad impact across quantum computing fields and serve as a foundation for a whole new family of large-scale dynamical quantum neural networks.