Alexander van Lomwel | Searcharxiv

arXiv2026

Quantum simulation of circular cluster interactions in a linear spin chain

The preparation of ground states of Hamiltonians with symmetries that are fundamentally different than those of the underlying device is a central challenge for quantum technologies. Here, we address this challenge with an analog protocol for the iconic generalized cluster Hamiltonian with the translational symmetry resultant from periodic boundary conditions based on a magnetization-preserving interaction on a linear geometry with open boundary conditions. Our results show that this goal can be achieved in a control duration that scales only moderately with the number of spins and Hamiltonian interaction complexity.

quant-ph↗

arXiv2026

Fast thermal state preparation beyond native interactions

While questions on quantum simulation of ground state physics are mostly focussed on the realization of effective interactions, most work on quantum simulation of thermal physics explores the realization of dynamics towards a thermal mixed state under native interactions. Many open questions that could be answered with quantum simulations, however, involve thermal states with respect to synthetic interactions. We present a framework based solely on unitary dynamics to design quantum simulations for thermal states with respect to Hamiltonians that include non-native interactions, suitable for both present-day digital and analogue devices. By classical means, our method finds the control sequence to reach a target thermal state for system sizes well out of reach of state-vector or density-matrix control methods, even though quantum hardware is required to explicitly simulate the thermal state dynamics. With the illustrative example of the cluster Ising model that includes non-native three-body interactions, we find that required experimental resources, such as the total evolution time, are independent of temperature and criticality.

quant-ph↗