A physical and universal model of bosonic computations with Solovay-Kitaev theorem

2026-09-30

AI Summary

This study addresses the challenge that drastic energy growth in bosonic quantum computing readily induces unphysical behavior, thereby causing universal compilation to fail. To overcome this, we propose an energy-preserving bosonic quantum computing model that treats energy as a constrained resource to restrict gate operations. We construct a natural universal gate set based on linear optics and Kerr interactions, circumventing previous no-go theorems. Furthermore, gate operations are generated via energy-preserving Hamiltonians, combined with the Solovay-Kitaev theorem to achieve efficient state synthesis and compilation. Our contributions demonstrate the universality and robustness of the proposed framework, successfully realizing Gottesman-Kitaev-Preskill (GKP) state preparation and high-precision simulation of arbitrary qubit unitary operations.

Abstract

Bosonic quantum systems are among the leading architectures for quantum information processing, offering continuous-variable degrees of freedom with strong error-correction capabilities. However, standard bosonic quantum computation models such as the Lloyd-Braunstein [Lloyd and Braunstein, 1999] and hybrid oscillator-qubit models [Brenner, Dias, and Koenig, 2025; Liu et al., 2026] permit dramatic energy growth, leading to unphysical computational power and the breakdown of fundamental algorithmic tools such as universal and efficient compilation [Brenner et al., 2026; Rudolph et al., 2025]. To address this, we introduce a new model of bosonic quantum computation, Bosonic Energy-Preserving Quantum Computation (BEQC), in which energy is treated as a computational resource. Namely, energy is supplied solely through input coherent states, and all gates are generated by energy-preserving Hamiltonians. Thus, by construction, dramatic energy growth is impossible, making the model physically grounded. We next show that BEQC is a computationally robust and universal model in many respects, including: (1. Computational power) BEQC efficiently simulates all polynomial-energy computations in existing models, and exactly recovers BQP in the polynomial energy setting. It further admits several complexity-theoretic upper bounds when varying the energy, precision, and space parameters of the model. (2. Universal gate sets and state synthesis) BEQC has natural universal gate sets based on linear optics and Kerr interactions. In particular, we obtain a Solovay-Kitaev theorem which circumvents previous no-go results. We give various applications, including (a) a protocol for engineering GKP states with rigorous preparation guarantees, (b) Fock state preparation to exponential precision, and (c) native Fock space simulation of any qubit-based unitary.

Problem

• bosonic quantum computation
• energy growth
• universal compilation
• Solovay-Kitaev theorem
• quantum information processing

Innovation

• Bosonic quantum computation
• Energy-preserving model
• Solovay-Kitaev theorem
• Universal gate sets
• GKP states