Not All SWAPs Have the Same Cost: A Case for Optimization-Aware Qubit Routing

• URL: http://arxiv.org/abs/2205.10596v1
• Date: Sat, 21 May 2022 13:36:44 GMT
• Title: Not All SWAPs Have the Same Cost: A Case for Optimization-Aware Qubit Routing
• Authors: Ji Liu, Peiyi Li, Huiyang Zhou
• Abstract summary: Near-term NISQ quantum computers and relatively long-term scalable quantum architectures do not offer full connectivity. A quantum compiler needs to perform qubit routing to make the circuit compatible with device layout. In this paper, we observe that the aforementioned qubit routing is not optimal, and qubit routing should textitnot be independent on subsequent gate optimizations.
• Score: 15.018468499770242
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Despite rapid advances in quantum computing technologies, the qubit connectivity limitation remains to be a critical challenge. Both near-term NISQ quantum computers and relatively long-term scalable quantum architectures do not offer full connectivity. As a result, quantum circuits may not be directly executed on quantum hardware, and a quantum compiler needs to perform qubit routing to make the circuit compatible with the device layout. During the qubit routing step, the compiler inserts SWAP gates and performs circuit transformations. Given the connectivity topology of the target hardware, there are typically multiple qubit routing candidates. The state-of-the-art compilers use a cost function to evaluate the number of SWAP gates for different routes and then select the one with the minimum number of SWAP gates. After qubit routing, the quantum compiler performs gate optimizations upon the circuit with the newly inserted SWAP gates. In this paper, we observe that the aforementioned qubit routing is not optimal, and qubit routing should \textit{not} be independent on subsequent gate optimizations. We find that with the consideration of gate optimizations, not all of the SWAP gates have the same basis-gate cost. These insights lead to the development of our qubit routing algorithm, NASSC (Not All Swaps have the Same Cost). NASSC is the first algorithm that considers the subsequent optimizations during the routing step. Our optimization-aware qubit routing leads to better routing decisions and benefits subsequent optimizations. We also propose a new optimization-aware decomposition for the inserted SWAP gates. Our experiments show that the routing overhead compiled with our routing algorithm is reduced by up to $69.30\%$ ($21.30\%$ on average) in the number of CNOT gates and up to $43.50\%$ ($7.61\%$ on average) in the circuit depth compared with the state-of-the-art scheme, SABRE.

Related papers

• LightSABRE: A Lightweight and Enhanced SABRE Algorithm [39.814077130655505]
  We introduce LightSABRE, a significant enhancement of the SABRE algorithm that advances both runtime efficiency and circuit quality. We have achieved a version of the algorithm in Qiskit 1.2.0 that is approximately 200 times faster than the implementation in Qiskit 0.20.1.
  arXiv  Detail & Related papers  (2024-09-12T19:19:59Z)
• SWAP-less Implementation of Quantum Algorithms [0.0]
  We present a formalism based on tracking the flow of parity quantum information to implement algorithms on devices with limited connectivity. We leverage the fact that entangling gates not only manipulate quantum states but can also be exploited to transport quantum information.
  arXiv  Detail & Related papers  (2024-08-20T14:51:00Z)
• Route-Forcing: Scalable Quantum Circuit Mapping for Scalable Quantum Computing Architectures [41.39072840772559]
  Route-Forcing is a quantum circuit mapping algorithm that shows an average speedup of $3.7times$. We present a quantum circuit mapping algorithm that shows an average speedup of $3.7times$ compared to the state-of-the-art scalable techniques.
  arXiv  Detail & Related papers  (2024-07-24T14:21:41Z)
• Improved Qubit Routing for QAOA Circuits [0.0]
  We develop a qubit routing algorithm with classical run time for the Quantum Approximate Optimization Algorithm (QAOA) We show that it improves upon existing state-of-the-art routing algorithms for QAOA circuits defined on $k$-regular as well as Erd"os-Renyi problem graphs of sizes up to $N leq 400$.
  arXiv  Detail & Related papers  (2023-12-26T10:26:10Z)
• Qubit efficient quantum algorithms for the vehicle routing problem on NISQ processors [48.68474702382697]
  Vehicle routing problem with time windows (VRPTW) is a common optimization problem faced within the logistics industry. In this work, we explore the use of a previously-introduced qubit encoding scheme to reduce the number of binary variables.
  arXiv  Detail & Related papers  (2023-06-14T13:44:35Z)
• Universal qudit gate synthesis for transmons [44.22241766275732]
  We design a superconducting qudit-based quantum processor. We propose a universal gate set featuring a two-qudit cross-resonance entangling gate. We numerically demonstrate the synthesis of $rm SU(16)$ gates for noisy quantum hardware.
  arXiv  Detail & Related papers  (2022-12-08T18:59:53Z)
• Robust Qubit Mapping Algorithm via Double-Source Optimal Routing on Large Quantum Circuits [11.391158217994782]
  Duostra is tailored to address the challenge of implementing large-scale quantum circuits on real hardware devices. It operates by efficiently determining optimal paths for double-qubit gates and inserting SWAP gates. It yields results of good quality within a reasonable runtime.
  arXiv  Detail & Related papers  (2022-10-04T01:47:11Z)
• Purification and Entanglement Routing on Quantum Networks [55.41644538483948]
  A quantum network equipped with imperfect channel fidelities and limited memory storage time can distribute entanglement between users. We introduce effectives enabling fast path-finding algorithms for maximizing entanglement shared between two nodes on a quantum network.
  arXiv  Detail & Related papers  (2020-11-23T19:00:01Z)
• Using Reinforcement Learning to Perform Qubit Routing in Quantum Compilers [0.0]
  We propose a qubit routing procedure that uses a modified version of the deep Q-learning paradigm. The system is able to outperform the qubit routing procedures from two of the most advanced quantum compilers currently available.
  arXiv  Detail & Related papers  (2020-07-31T10:57:24Z)
• 2D Qubit Placement of Quantum Circuits using LONGPATH [1.6631602844999722]
  Two algorithms are proposed to optimize the number of SWAP gates in any arbitrary quantum circuit. Our approach has a significant reduction in number of SWAP gates in 1D and 2D NTC architecture.
  arXiv  Detail & Related papers  (2020-07-14T04:09:52Z)
• Improving the Performance of Deep Quantum Optimization Algorithms with Continuous Gate Sets [47.00474212574662]
  Variational quantum algorithms are believed to be promising for solving computationally hard problems. In this paper, we experimentally investigate the circuit-depth-dependent performance of QAOA applied to exact-cover problem instances. Our results demonstrate that the use of continuous gate sets may be a key component in extending the impact of near-term quantum computers.
  arXiv  Detail & Related papers  (2020-05-11T17:20:51Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.