A Computational Framework for Simulations of Dissipative Non-Adiabatic Dynamics on Hybrid Oscillator-Qubit Quantum Devices

TL;DR

This work introduces a computational framework for simulating non-adiabatic vibronic dynamics on hybrid oscillator-qubit hardware, incorporating environment-induced dissipation through engineered channels and validating the approach on a tri-site photosynthetic chromophore model. It maps the vibronic Hamiltonian to a cQED platform, extends to a 1D chromophore array, and uses a native cQED ISA with Trotterization to realize real-time evolution, including dispersive vibronic couplings via XX/YY interactions and conditional-phase gates. The authors provide detailed circuit compilations, resource estimates, and extensive numerical results showing accurate Lindblad-like dynamics and tunable energy-transfer pathways under amplitude damping and dephasing, with robustness to representative hardware noise. The findings demonstrate the practicality of near-term quantum devices for open quantum system simulations in chemistry, and delineate clear paths toward scalable, error-mitigated vibronic simulations and potential quantum advantage in chemical dynamics.

Abstract

We introduce a computational framework for simulating non-adiabatic vibronic dynamics on circuit quantum electrodynamics (cQED) platforms. Our approach leverages hybrid oscillator-qubit quantum hardware with mid-circuit measurements and resets, enabling the incorporation of environmental effects such as dissipation and dephasing. To demonstrate its capabilities, we simulate energy transfer dynamics in a triad model of photosynthetic chromophores inspired by natural antenna systems. We specifically investigate the role of dissipation during the relaxation dynamics following photoexcitation, where electronic transitions are coupled to the evolution of quantum vibrational modes. Our results indicate that hybrid oscillator-qubit devices, operating with noise levels below the intrinsic dissipation rates of typical molecular antenna systems, can achieve the simulation fidelity required for practical computations on near-term and early fault-tolerant quantum computing platforms.

Figures (13)

• Figure 1: (a) Photosynthetic antenna model system, composed of three chromophores representing distinct pigments within a protein. One elementary problem is to determine if an initial electronic excitation on chromophore $A$ has a dominant energy transfer pathway, and if so, whether it favors energy transfer to chromophore $B$ or $C$. (b) Proposed cQED modular hardware for simulating vibronic dynamics of a three-site chromophore system. High-frequency (red circles) and low-frequency (yellow circles) cavities represent vibrational modes. A SNAIL device mediates coupling between adjacent cavities. High-frequency cavities are coupled to transmon qubits (shown in purple), representing the ground and excited electronic states of each chromophore, while ancillary qubits for low-frequency cavities are shown in teal blue.
• Figure 2: Quantum circuit realizations of different dissipation channels, where the system qubit $\ket{\phi}$ undergoes dissipation via coupling to the environment, modeled by an ancillary qubit initialized in the ground state $\ket{0}$. (a) Amplitude damping channel, where $\theta$ is obtained from Eq. \ref{['Eq:angle_AMP']}; (b) Excitation channel, where $\theta$ is obtained from Eq. \ref{['Eq:angle_EXC']}; (c) Dephasing channel, where $\theta$ is obtained from Eq. \ref{['Eq:angle_DEP']}; (d) General dissipation channel for the spin-boson model in Eq. \ref{['eq:HT']}. The $\mathrm{R}_y$ rotation angle $\theta$ for each component channel is calculated with $t$ being replaced by the small time step $\tau$ and the damping rates provided in Table \ref{['tab:para_lindblad_SBM']}. (e) Real-time evolution of the spin-boson model, where each Trotter layer consists of the evolution unitary $U_\tau = e^{-i H_S \tau }$, followed by the general dissipation channel $\mathcal{E}_{\tau}$.
• Figure 3: Proposed modular cQED architecture for simulating vibronic dynamics in a 1D molecular chain. Each colored box represents a hardware unit corresponding to a single chromophore. For the two boundary chromophores ($\xi=1, N$), only the high-frequency vibrational modes are considered. Intermediate chromophores $\xi\in[2,N-1]$ are modeled with both high- (red circles) and low-frequency (orange circles) cavities, coupled with SNAILs for efficient cavity-cavity interactions. Transmon qubits (shown in purple) represent the electronic states, while ancillary transmon qubits are depicted in teal blue.
• Figure 4: (a) Two circuit compilations for $\sigma^x\sigma^x$ interaction terms between adjacent chromophores. These circuits reduced to qubit operations and transmon-cavity dispersive interactions on the low-frequency mode $\xi_1$. The second circuit implicitly requires a pair of conjugate SWAP operations to mediate non-nearest-neighbor CNOT gates. (b) Circuit compilation for $\sigma^y\sigma^y$ interaction terms between adjacent chromophores. The $H_{2,XX}$ block is implemented as shown in (a). For the cQED hardware layout in Fig. \ref{['fig:modular-cQED']}, the $(\xi-1)_0$ qubit shall be placed before the $\xi_0$ qubit.
• Figure 5: Population dynamics of the spin-boson model. The results compare Lindblad dynamics simulated using QuTiP with the Trotterized quantum circuit in Fig. \ref{['fig:noise_circuit_SBM']} (e). $P_0$ and $P_1$ denote the probabilities of measuring $\ket{0}$ and $\ket{1}$, respectively, for the system qubit. Each data point represents the average measurement from 2000 shots.