2025-07-10 –, Room 318
Rydberg atoms offer unique quantum properties that enable radio-frequency sensing capabilities distinct from any classical analogue; however, large parameter spaces and complex configurations make understanding and designing these quantum experiments challenging. Current solutions are often developed as in-house, closed-sourced software simulating a narrow range of problems. We present RydIQule, an open-source package leveraging tools of computational python in novel ways to model the behavior of these systems generally. We describe RydIQule’s approach to representing quantum systems using computational graphs and leveraging numpy broadcasting to define complete experiments. In addition to discussing the computational challenges RydIQule helps overcome, we outline how collaboration between physics and computational research backgrounds has led to this impactful tool.
Quantum sensing is a fundamentally new technology with no classical analogue. This rapidly expanding research field enables unprecedented capabilities in navigation, time-keeping, magnetometry, and electrometry. A particular focus of our work is using Rydberg atomic sensors for radio-frequency field sensing. These sensors leverage quantum states that are highly sensitive to ambient electric fields, enabling omniband operation spanning from DC to a terahertz with many simultaneous frequencies in a single device. While they show great promise, designing these devices and understanding their behavior can pose many challenges.
The physics behind quantum sensors, especially in the context of prototyping experiments, makes efficient simulation difficult. A quantum system of this type consists of a set of discrete energy levels with lasers or radio-frequency fields coupling them. The number of levels can easily exceed 100, and the couplings between them can be arbitrarily complicated. Coupled sets of ordinary differential equations describe the dynamics of the system, their size scaling with the square of the number of levels present in the system. When simulating experiments in which laser parameters are swept over a range of values, each combination of parameters yields a unique set of differential equations, leading to even further difficulties. As the dimension of the parameter space increases, the number of equation sets increases exponentially.
Answering these needs requires a common tool for modeling experiments and designing novel classes of devices. To this end, we have developed the Rydberg Interactive Quantum Module (RydIQule), a tool leveraging principles of scientific python to enable efficient simulation.
The first challenge we address is choosing a data structure to represent the quantum system that is both expressive of the physics and flexible enough to handle the wide variety of problems in Rydberg sensing and beyond. Our novel insight is that atomic states and the fields that couple them are naturally represented as the nodes and edges of a directed graph. The networkx package provides an easy-to-use implementation, allowing us to store all relevant information of a system within the graph. By reading parameters from the graph, RydIQule has enormous algorithmic flexibility in generating differential equations describing the dynamics of the system.
RydIQule handles the exponential parameter space by leveraging numpy’s broadcasting operations in ways that suit experiment simulation well. Casting parameter arrays to the correct shape at the outset ensures the rest of the procedure can be scripted without any consideration of matrix shape. Furthermore, it allows extracting high-dimensional tensor diagonals from the parameter space. This technique simulates two parameters swept in parallel (common in optical physics experiments), and reduces the dimensionality of the parameter space by trimming irrelevant equations.
RydIQule has already seen growing use because it is both intuitive to physicists and sound in software design principles. It is a demonstration of insights from fields like machine learning leading to transformative changes in researchers’ software tools. Atomic sensing is not unique in its need for such a tool, and we encourage more dialogue between science and software to rapidly accelerate research across fields.
RydIQule’s source is available on github with documentation on readthedocs. Our peer-reviewed article introducing it to the research community is available at Computer Physics Communications.
Lead developer for the the Rydberg Interactive Quantum Module (RydIQule), an open-source tool for research labs to model a broad range of Quantum Sensing experiments. Working for the Army Research Lab researching Quantum Sciences. Passion for bridging the gap between physics and software, and building open tools to accelerate research. Current interests include quantum technology (including its limitations) and classical simulation of quantum circuits.