Advancing Quantum Simulation of the Unruh Effect: Thermal Collapse and Decoherence

Fangzhou Jin, Hongwei Chen, Xing Rong +8 more

Zehua Tian, Jiliang Jing

Xu Cheng, Yue Li, Zehua Tian +3 more

Ming‐Ming Du, Dong Wang, Ye Liu

Zuhair Ahmed

Abstract The Unruh effect, a cornerstone of quantum field theory, predicts that an accelerating observer perceives a thermal bath of particles in a vacuum, bridging quantum mechanics and relativity. This study presents the first successful simulation of the Unruh effect on real quantum hardware, conducted at the Centre of Excellence for Technology, Quantum, and AI Canada (CETQAC). Using a two-qubit quantum circuit executed on IBM’s su perconducting qubits via Qiskit Runtime Services, we encoded the effect’s key features: quantum superposition, Bogoliubov transformations, and thermodynamic signatures. Re sults demonstrate a strong concentration in the |11⟩ basis state, with metrics such as pu rity (0.5), entropy (1.0), entanglement entropy (1.0), fidelity (0.46), and expectation value (Z =0.0) aligning with theoretical predictions. Visualizations, including statevector plots and Q-sphere representations, confirm the simulation’s success. This work advances quan tum thermodynamics and relativistic quantum physics, establishing Canada as a leader in quantum computing applications.

Shoukang Chang, Yawen Tang, Wei Ye +3 more

Gaussian quantum channels constitute a pivotal physical framework for characterizing the dynamics of Gaussian quantum states. Extensive scholarly attention has been devoted to the estimation of parameters associated with Gaussian channels. However, while previous research has predominantly focused on parameter estimation within inertial frames, the noninertial scenario, particularly in the context of the Unruh effect, remains largely unexplored. In this paper, we analyze the impact of the Unruh effect on the estimation precision of Gaussian channel parameters, with a specific focus on thermal attenuator and thermal amplifier channels. Our findings reveal that the Unruh effect significantly degrades the precision of single-parameter estimation for Gaussian channel parameters when employing both the input coherent state and squeezed vacuum state. For the two-parameter estimation, we further demonstrate that the quantum Cramér-Rao bound serves as an asymptotically achievable precision limit. Consistent with the single-parameter case, the Unruh effect exerts a detrimental impact on the precision of two-parameter estimation. Notably, heterodyne measurement is near-optimal for both single- and two-parameter estimation in the limit of high acceleration or large thermal mean numbers. These results provide crucial theoretical insights and practical guidance for advancing quantum parameter estimation in a relativistic context.