Quantum error mitigation may simulate complex physics without extra qubits

Hiroki Kuji of Tokyo University of Science and colleagues have developed a new protocol that simulates complex physics governed by non-Hermitian Hamiltonians without requiring additional qubits. The work combines a Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) evolution with stochastic quantum error mitigation (QEM) to model these systems on near-term quantum devices, a feat previously hindered by the need for ancilla qubits, controlled time evolution and continuous monitoring. The error mitigation layer relies solely on single-qubit operations, offering a potentially scalable approach to investigating exotic dynamics beyond standard quantum mechanics. The researchers validated their method through simulations of asymmetric-hopping models and open XXZ spin chains. This approach allows for the simulation of non-Hermitian dynamics without relying on deep circuits requiring controlled unitary primitives or additional qubits, addressing a significant challenge for near-term quantum devices. A key feature of this work is the exclusive use of single-qubit operations…