Reduced Bloch vector (X,Z plane)
Unit-radius reference disc
Quantum simulation, as a field, means using a controllable quantum system — often a gate-based quantum computer — to compute the time evolution of another quantum system that is otherwise intractable to simulate classically. This page runs the exact same digital quantum-simulation circuit as the 3D version, rendered as a flat 2D chain: N spins under the transverse-field Ising Hamiltonian, evolved with a first-order Trotter-Suzuki decomposition that alternates the non-commuting coupling and field terms as a sequence of gates applied to the full statevector. Tune the coupling J, the transverse field h, and — most importantly — the Trotter step size, and watch the simulated state's fidelity against a much finer continuum reference degrade as steps get coarser, exactly the tradeoff that limits real digital quantum simulators today.