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Software abstraction: The missing link to commercially viable quantum computing

Learn how software abstraction helps automates calibration, optimizes workloads, and simplifies quantum programming.

Quantum computers promise revolutionary leaps in processing power but come with equally monumental complexity. For most users, especially those outside research environments, accessing quantum hardware still feels like navigating a maze of low-level research-grade tools, clunky calibration routines, and partial error-handling solutions only manageable by a select group of experts. 

As we eye a transition of quantum computing hardware from research labs into data centers, how can this user experience possibly deliver on the technology’s true promise? 

In our last quantum data center article, we introduced the answer. We need to move beyond considering only the “bare metal” hardware and build the same kinds of abstraction layers that make classical computing accessible to the world. Here we’ll dive deeper and show how that shift is already underway.

Today, quantum hardware vendors broadly deliver “bare metal” computing engines, accompanied only by the software required to execute low-level tasks. This creates a pressing issue in quantum computing because the machines are not only incredibly complex to use but also inherently fragile, suffering from hardware errors. Those errors are manifested as failed algorithms without any clear warning of a problem - the issue is simply endemic to the QPUs themselves and is, in general, left to the user to resolve. 

Accordingly, in most research settings, individual developers bear responsibility for deploying solutions to stabilize the hardware and combat errors as part of executing their computational workloads. However, this requires extensive PhD-level quantum computing and quantum physics expertise; it’s the model of scientist end-users, not broad commercial adoption.

Without a major change, anyone looking to take advantage of quantum computing delivered in the data center will therefore face major pressure to upskill on the necessary hardware management tasks. They are forced to complete expert-driven bootup, frequent interventions to maintain adequate performance, and to deploy custom tools to enable users to execute useful workloads with the right integrated performance management. That is a significant user tax to take advantage of a new technology and likely poses an insurmountable barrier for most candidate early adopters. 

Instead, data center operators focused on delivering maximum value to end users can meaningfully lift this burden by adding the right software abstraction to quantum computers. 

Quantum Infrastructure Software delivers this essential abstraction, turning bare-metal QPUs into useful devices, much the way data center providers integrate virtualization software for their conventional systems. Current offerings cover all of the functions typically associated with the classical BIOS up through virtual machine Hypervisors, extending to developer tools at the application level. 

Software-driven abstraction of quantum complexity away from the end users lets anyone, irrespective of their quantum expertise, leverage quantum computing for the problems that matter most to them. Here we identify three key areas where abstraction can deliver huge dividends, with solutions available today to implement said abstraction:

a. Abstract hardware maintenance

The first quantum complexity users must overcome is device maintenance and calibration; these sensitive and temperamental devices need continuous attention to keep their performance at acceptable standards. Unlike traditional computer hardware, quantum hardware is non-deterministic and volatile. This means a simple routine of calibration steps is not enough to wrangle the hardware consistently into a usable state. 

Instead, a much more adaptable process is required. Calibration software must be robust enough to navigate the complex space of qubits, couplers, resonators, and more to convert those discrete components into an orchestrated, high-performance quantum information processor. Furthermore, it must continually factor in the ever-changing, noisy influence of the broader environment. It has to work every time with the “push of a button”; only through the delivery of repeatable, high-quality results can this problem be truly abstracted from the user.

Fortunately, Boulder Opal from Q-CTRL enables this fully autonomous hardware bootup experience. From a cold start, the package will “auto-boot” the device, tune to peak performance, and periodically recalibrate to keep the system stable and performant, all with no operator intervention. It does this by combining years of human intelligence in control with physics-informed AI automation to deliver peak system performance, every time.

Autonomy in this setting saves time and costs for data center and HPC operators, and relaxes the need to have on-call PhD experts to tweak system performance or troubleshoot inevitable device failures. Turn it on, and a short time later the system is – and stays ready to go.

b. Abstract workload execution on hardware

With a finely tuned quantum computer accessible, a user must still execute many tasks to extract useful answers from the QPU, in analogy with the need for careful memory management required to gain practical acceleration with GPUs. 

Most importantly, in executing a real workload, they must convert high-level “assembly-language” logical definitions of quantum applications into hardware-specific “machine-language” instructions that account for the details of the QPU in use, and deploy countermeasures where errors might leak in. These are typically tasks that can only be handled by (expensive!) specialists in quantum-device operation.

Fire Opal, again from Q-CTRL, is the first and only infrastructure software package that automates a comprehensive execution and error suppression pipeline to give users the best chance of running a successful workload, no PhD required. Together with Boulder Opal, Fire Opal takes the auto-booted machine and automatically implements compilation (conversion from logical to machine language), along with all required error-reduction technology, addressing errors everywhere they occur: from individual gates to complex circuits. It accepts a logical algorithm and outputs the optimized machine instructions for each specific QPU family, complete with all necessary countermeasures to prevent errors from creeping in.

All of this technology, shown to improve bare-metal performance by thousands of times, is fully autonomous and invisible to the user.

The result of this abstraction is a QPU that is “virtualized” so an end-user can simply program at a logical level and achieve useful results without responsibility for the details of workload execution. This is strikingly similar to the way VMware hypervisors break the link between a specific physical processor and an abstracted computational resource, and carries opportunities equally profound for application development.

c. Abstract the quantum computer completely

Maturing from research-grade tests to running meaningful quantum computing workloads still requires a lot of effort: design of efficient quantum algorithms, quantum data routing/management, classical/quantum interfacing for hybrid computing. The effective assembly language typically used to program quantum computers - the quantum circuit representation - is quite inadequate for these tasks.

Now, by bundling quantum hardware running performance-management infrastructure software with developer tools and application modules, quantum computing can be abstracted up to the problem level, dramatically expanding accessibility and utility.

Starting with a virtualized QPU running performance-management quantum infrastructure software, Q-CTRL’s partner integrations can simplify algorithmic design and deployment at commercially relevant scales. Users can either automate quantum circuit design given a specific quantum algorithm, or simply program their problems using common languages like Python, while the intermediary software solutions handle all cross-compilation down to the assembly language, as well as handling all post-processing and analysis. 

As a concrete example, the Fire Opal optimization solver takes as input a mathematical optimization problem defined using the same inputs as classical solvers like Gurobi or CPlex. Once the problem is defined, the solver generates all relevant quantum circuits, incorporates error-reducing performance management, and orchestrates the hybrid quantum/classical loop. The user programs the same way they would solve a problem on conventional hardware, and all other aspects are invisibly abstracted. It’s quantum computing without knowing you’re using a quantum computer!

Here is a list of essential software bundle for quantum abstraction:

Category Product and vendor Service
Infrastructure software Boulder Opal from Q-CTRL Quantum autobooter*: Automation for hardware management, calibration, and gate-level tuneup
Infrastructure software Fire Opal from Q-CTRL Quantum hypervisor: QPU performance management via active device and circuit-level error suppression and hardware abstraction/virtualization
Developer tools Qiskit, ClassiQ, Wolfram Quantum circuit design, synthesis, and test for programmers focused on development at the “assembly language” quantum circuit level
Application modules qBraid, qCentroid, aqarios, algorithmiq, Fire Opal Optimization solver Prepackaged quantum algorithms for targeted problem classes, fully abstracted from quantum circuits, for end users who do not focus specifically on quantum programming.

* Note: autobooters are shipped with complete systems but must be purchased separately when selecting to build a custom system around a QPU core.

Q-CTRL’s infrastructure software (represented by the three purple layers) provides the key abstraction layers, moving from bare quantum hardware to enabling users to program at the application and problem level.

By automating system calibration, optimizing workload execution, and enabling end-users to program at the problem level, not the quantum circuit level, quantum infrastructure software solutions are redefining what it means to use a quantum computer. The age of specialist-only access is giving way to broad utility, thanks to intelligent software abstractions that make quantum computing accessible and powerful.

This article was originally published in Data Center Dynamics under the same title.

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