Because evolution is unitary.
How to Run Programs on Quantum Computers for Free
The Unitary Fund team and Advisory Board often get asked this question: “How can I run programs on quantum computers?” Today there are a lot of options for free cloud-access to quantum computing services and we’ve taken a shot at summarizing some of the well known ones. If you know of platforms or programs that we have missed then please do reach out to firstname.lastname@example.org
IBM Quantum regularly releases free to access hardware on an a-la-carte selection of QPUs (although some get routinely decommissioned, such as the beloved ibmq-armonq, the first to provide pulse-level access). Many IBM Quantum QPUs are free to access, while some are only for partnerships. There are also special access programs for educators and researchers.
AWS Braket is fully integrated in the AWS dashboard as one of its existing services and has many devices. It provides one hour per month of free credits for simulation but not yet a default mechanism to access QPUs or free credits for QPUs. They run a wider cloud credit for research program that includes quantum, although you need to be full-time in academia to apply. Unitary Fund obtained several credits by asking, so it is always worth trying to contact the Braket team.
Azure Quantum provides $500 free per each provider (IonQ, Quantinuum, etc.) upon signing in + more credits for approved research projects.
IonQ has a research credit program with the call closing soon, on June 30th 2022. Hopefully there will be more!
Quantum Inspire is an initiative by TU Delft in The Netherlands. As far as I know, it is the only provider of quantum-dot-based spin qubits publicly available on the cloud, for free. The downside is that, last time I checked, they have sort of a cQASM interface that is not exactly OpenQASM. Plus, the devices can be off the grid for maintenance.