Why pulse-level access is important:
In principle, quantum circuit execution can happen in a black box - send a circuit somewhere and get back the results. However, transparency is crucial for showing that no unintended optimisations are skewing the results, and one can reproduce research work. Learning how quantum circuit execution really works, and optimising the performance requires visibility and control of the execution down to details.
Detailed visibility and control of quantum circuit execution helps quantum engineers, computer scientists, and students learn and further improve and optimise what really happens when going from circuit representation down to pulses.
Improving and optimising the compilation is crucial on the way towards error correction – for correction to work, errors need to remain below a certain threshold, and software needs to be performant even with future large quantum processing units (QPUs).
“Our software allows the user to control the generation and execution of pulse-level instruction schedules on a quantum computer,” explains Janne Mäntylä, the Head of Software Development. “IQM Pulla allows reducing gate errors by enabling users to try out novel pulse shapes and comparing those to textbook pulses.”
How IQM Pulla works:
IQM Pulla is our software allowing visibility and access to the very details underlying the quantum circuit representation. IQM Pulla is a Python package that can be installed onto the end user's computer.
The main functionality of IQM Pulla is the detailed step-by-step compilation process starting from a quantum circuit and ending in the final pulse schedule that can be sent to execution - all fully transparent in the end-user computer.
A pulse schedule is a description of the exact timings and shapes of the control pulses that the control electronics will send to the various qubits, couplers, and readout lines on the QPU.
As IQM Pulla allows modifying, or even inserting your own steps to the compilation, we are unlocking capabilities in error suppression and error mitigation development. Another important thing is that the user can really see the final pulse schedule and trust it’s not further modified but executed exactly as-is.
The key advantage of IQM Pulla is the visibility and the ability to change the details of how a quantum circuit is compiled into a pulse schedule. In addition, with pulse-level access, end-users can:
- access and modify the calibration data to be used for the circuit-to-schedule compilation.
- view and modify the default implementations of quantum gates.
- define custom implementations of quantum gates.
- define new composite gates out of native gates and set their calibration data.
- control the multi-step compilation procedure and edit the intermediate data.
- and use custom pulse shapes.
Already, customers such as Leibniz Supercomputing Centre (LRZ) Germany, VTT Technical Research Centre in Finland, and Eviden in France have pulse-level access through our on-premises quantum computers.
“IQM Pulla also allows squeezing out more computational performance from hardware by allowing and opening access into pulse shapes, error mitigation, and error suppression techniques,” discloses Mäntylä, noting that “We are working on making IQM Pulla available also through IQM Resonance, our cloud service in the second quarter of this year.”
Mäntylä states that for the widespread usage of quantum computing, a strong and high-performing software stack is essential to harness all benefits.
To get started and explore more on pulse-level access, have a look at IQM Pulla documentation and reach out to our team here.
