Keynote: The First Decade of Open Quantum

### Overview Ten years ago, IBM placed the first five-qubit quantum processor on the cloud, transforming quantum computing from an isolated laboratory endeavor into an accessible, open-source technology ecosystem. In this keynote, the speaker reflects on the decade-long journey of open quantum computing, exploring why classical systems fail to accurately model the quantum physical world, how open-source software like Qiskit catalyzed adoption, and the substantial technical scaling achieved from 5 qubits to non-simulatable devices exceeding 100 qubits.

### Key Topics - **Foundations of Quantum Computing**: The macroscopic world masks quantum effects, but the microscopic realm—such as transistors, polymers, and proteins—is inherently governed by quantum mechanics. Classical computing relies on approximations on supercomputers because digital bits cannot natively reflect quantum phenomena. Quantum computing leverages qubits, superposition, entanglement, and interference to solve problems that are computationally impossible or intractable classically. - **Application Pillars**: Quantum advantages are currently pursued across four main domains: Hamiltonian simulation (molecular and protein modeling), optimization problems (such as the traveling salesman problem), machine learning, and differential equations (crucial for large-scale aerodynamic simulations). - **The Rise of Qiskit**: From an initial web drag-and-drop experiment on a 5-qubit device that drew over 20,000 users in two weeks, IBM recognized the need for a comprehensive programming stack. This led to Qiskit (Quantum Information Science Toolkit), released under the Apache 2 license. It now underpins over 5,000 research papers and more than 7,000 dependent projects, offering a pluggable hardware interface across various quantum systems.

### Technical Details - **The 100-Qubit Threshold**: Processors with fewer than 30 qubits can be simulated on a laptop, and those with fewer than 50 qubits on supercomputers. However, because resource requirements scale exponentially, surpassing the 100-qubit barrier in 2021 created a non-simulatable operational regime where hardware executes calculations classical machines cannot replicate. - **Qiskit Add-ons and the SQD Algorithm**: To help users advance beyond a handful of qubits, open-source Qiskit add-ons were developed to encapsulate cutting-edge research algorithms. The SQD algorithm, developed over a year of research by IBM and partner institutions, provided repeatable solutions that external teams rapidly adopted. - **Core Rewrite in Rust**: While Qiskit began in Python, broadening integration with established scientific codebases required interoperability. The core of Qiskit was rewritten in Rust, providing native performance and C-binding interfaces to support languages such as C++, Fortran, and Julia. - **Experimental & Molecular Milestones**: Collaborative work with Oak Ridge National Laboratories demonstrated quantum simulations matching physical experimental neutron gun scatter patterns through magnetic copper crystals. Additionally, molecular modeling by the Cleveland Clinic scaled over 18 months from 10 atoms to modeling trypsin, a molecule comprising over 12,000 atoms.

### Takeaways Over the past decade, open-source software and cloud availability moved quantum computing from bespoke lab setups with oscilloscopes and patch cables to an always-on fleet of processors over 100 qubits. The speaker concludes with a call to action for developers and researchers to shape the next decade of quantum computing using Qiskit and accessible cloud plans.