Quantum Circuit Mapping Strategies for Modern Hardware

Our recent benchmarks show that the Qiskit transpiler works very well by default (https://lnkd.in/e98wniXY). But it gets even better if you learn to customize it for your specific circuits. Here’s one example: Hamiltonian simulation circuits are the workhorse of quantum algorithms. These circuits are characterized by sequences of (potentially high-weight) Pauli rotations. Rustiq developed by Timothée Goubault de Brugière and Simon Martiel is a method for smart synthesis of these circuits by taking into account the structure of the Clifford and Pauli groups. By considering the commutation relations between the Pauli terms and finding low-cost Clifford basis changes to map between the different Paulis, it can synthesize the full Pauli sequence into efficient one- and two-qubit gates. The Clifford frame that is tracked in the process can additionally be absorbed into the observable that is measured at no additional cost. We see a substantial reduction in gate count and depth when we apply Rustiq on Hamiltonian simulation circuits in Benchpress. Qiskit users can access Rustiq as a transpiler plugin in version 1.3, and customize their pass manager’s High Level Synthesis stage to use it. Reference paper is found here https://lnkd.in/eDGbe4An and code here https://lnkd.in/e6uPHDZR 

Scaling neutral atom quantum compilation to thousands of qubits—now with less overhead and new hybrid mapping capabilities! 🚀 Neutral atom quantum devices are growing fast, and compiling circuits for them has been a major challenge. Over the past months, our team worked hard to tackle this challenge—leading to a major update of the Munich Quantum Toolkit. With MQT QMAP v3.5.0, we introduce a new approach that makes compilation for zoned neutral atom architectures far more scalable. The results speak for themselves: ✅ Handles thousands of qubits ✅ Cuts rearrangement overhead by 28.1% on average This release also significantly extends the Hybrid Neutral Atom Mapper, which now supports multiple advanced mapping and routing techniques: ✅ Support Bridge gates, Pass-by moves, and Flying ancillas ✅ Hybrid synthesis routing for iterative circuit constructions Together, these additions enable more flexible, expressive, and efficient compilation of realistic neutral atom workloads. 📄 For those who want the details: we've just published the paper on arXiv, “Search Smarter, Not Harder: A Scalable, High-Quality Zoned Neutral Atom Compiler.” 🔗 Find both the paper and the tool (of course in open-source) via the links below. 👏 Big thanks to everyone who contributed—especially Yannick Stade, Ludwig Schmid, and Lukas Burgholzer! #quantumcomputing #compilation #neutralatoms #mapping #routing #mqt #qmap #opensource

⚛️ Not All Qubits are Utilized Equally 📑 Improvements to the functionality of modern Noisy Intermediate-Scale Quantum (NISQ) computers have coincided with an increase in the total number of physical qubits. Quantum programmers do not commonly design circuits that directly utilize these qubits; instead, they rely on various software suites to algorithmically transpile the circuit into one compatible with a target machine’s architecture. For connectivity-constrained superconducting architectures in particular, the chosen syntheses, layout, and routing algorithms used to transpile a circuit drastically change the average utilization patterns of physical qubits. In this paper, we analyze average qubit utilization of a quantum hardware as a means to identify how various transpiler configurations change utilization patterns. We present the preliminary results of this analysis using IBM’s 27-qubit Falcon R4 architecture on the Qiskit platform for a subset of qubits, gate distributions, and optimization configurations. We found a persistent bias towards trivial mapping, which can be addressed through increased optimization provided that the overall utilization of an architecture remains below a certain threshold. As a result, some qubits are overused whereas other remain underused. The implication of our study are many-fold namely, (a) potential reduction in calibration overhead by focusing on overused qubits, (b) refining optimization, mapping and routing algorithms to maximize the hardware utilization and (c) pricing underused qubits at low rate to motivate their usage and improve hardware throughput (applicable in multi-tenant environments). ℹ️ Pope & Gosh - School of Computer Science and Engineering Pennsylvania State University Centre County, PA, USA - 2025