Quantum simulation of the wavefunction to probe frustrated Heisenberg spin systems

TL;DR

This paper demonstrates an analog quantum simulation of a four-spin-1/2 system to explore frustration and entanglement in Heisenberg spin models, providing insights into complex quantum states relevant for exotic matter.

Contribution

It introduces a method for simulating frustrated Heisenberg spin systems using photonic qubits, enabling direct observation of ground states and entanglement dynamics.

Findings

Ground-state energies and correlations measured

Frustration induces transition from localized to resonating valence-bond states

Entanglement monogamy observed among particles

Abstract

Quantum simulators are controllable quantum systems that can reproduce the dynamics of the system of interest, which are unfeasible for classical computers. Recent developments in quantum technology enable the precise control of individual quantum particles as required for studying complex quantum systems. Particularly, quantum simulators capable of simulating frustrated Heisenberg spin systems provide platforms for understanding exotic matter such as high-temperature superconductors. Here we report the analog quantum simulation of the ground-state wavefunction to probe arbitrary Heisenberg-type interactions among four spin-1/2 particles . Depending on the interaction strength, frustration within the system emerges such that the ground state evolves from a localized to a resonating valence-bond state. This spin-1/2 tetramer is created using the polarization states of four photons. The single-particle addressability and tunable measurement-induced interactions provide us insights into entanglement dynamics among individual particles. We directly extract ground-state energies and pair-wise quantum correlations to observe the monogamy of entanglement.