The evolution of a quantum system interacting with an environment can be described as a unitary process acting on both the system and the environment. In this framework, the system's evolution can be predicted by tracing out the environmental degrees of freedom. Here, we establish a precise mapping between the global unitary dynamics and the quantum operation involving the system, wherein the system is a single qubit, and the environment is modeled as a discrete lattice space. This approach enables the implementation of arbitrary noise operations on single-polarization qubits using a minimal set of three liquid-crystal metasurfaces, whose transverse distribution of the optic axes can be patterned to reproduce the target process. We experimentally validate this method by simulating common noise processes, such as phase errors and depolarization. Besides providing a practical solution for quantum state purification, this work demonstrates a versatile approach for the simulation of open qubit dynamics, with potential implications for quantum error correction and environment-induced quantum phase transitions.The evolution of a quantum system interacting with an environment can be described as a unitary process acting on both the system and the environment. In this framework, the system's evolution can be predicted by tracing out the environmental degrees of freedom. Here, we establish a precise mapping between the global unitary dynamics and the quantum operation involving the system, wherein the system is a single qubit, and the environment is modeled as a discrete lattice space. This approach enables the implementation of arbitrary noise operations on single-polarization qubits using a minimal set of three liquid-crystal metasurfaces, whose transverse distribution of the optic axes can be patterned to reproduce the target process. We experimentally validate this method by simulating common noise processes, such as phase errors and depolarization. Besides providing a practical solution for quantum state purification, this work demonstrates a versatile approach for the simulation of open qubit dynamics, with potential implications for quantum error correction and environment-induced quantum phase transitions.

arXiv:2412.04701Physical Review ResearchJun 6, 20251 citation

Quantum state engineering with photonic qubits

Klaus M. Gheri, Päivi Törmä, P. Zoller

Acta Physica Slovaca Reviews and TutorialsAug 1, 19990 citations

Simulating open quantum systems in integrated photonics

Nicola Maraviglia

Jan 1, 20200 citations

Experimental implementation of fully controlled dephasing dynamics and synthetic spectral densities

Zhao‐Di Liu, Henri Lyyra, Yong-Nan Sun +5 more

Engineering, controlling, and simulating quantum dynamics is a strenuous task. However, these techniques are crucial to develop quantum technologies, preserve quantum properties, and engineer decoherence. Earlier results have demonstrated reservoir engineering, construction of a quantum simulator for Markovian open systems, and controlled transition from Markovian to non-Markovian regime. Dephasing is an ubiquitous mechanism to degrade the performance of quantum computers. However, all-purpose quantum simulator for generic dephasing is still missing. Here, we demonstrate full experimental control of dephasing allowing us to implement arbitrary decoherence dynamics of a qubit. As examples, we use a photon to simulate the dynamics of a qubit coupled to an Ising chain in a transverse field and also demonstrate a simulation of nonpositive dynamical map. Our platform opens the possibility to simulate dephasing of any physical system and study fundamental questions on open quantum systems.Engineering, controlling, and simulating quantum dynamics is a strenuous task. However, these techniques are crucial to develop quantum technologies, preserve quantum properties, and engineer decoherence. Earlier results have demonstrated reservoir engineering, construction of a quantum simulator for Markovian open systems, and controlled transition from Markovian to non-Markovian regime. Dephasing is an ubiquitous mechanism to degrade the performance of quantum computers. However, all-purpose quantum simulator for generic dephasing is still missing. Here, we demonstrate full experimental control of dephasing allowing us to implement arbitrary decoherence dynamics of a qubit. As examples, we use a photon to simulate the dynamics of a qubit coupled to an Ising chain in a transverse field and also demonstrate a simulation of nonpositive dynamical map. Our platform opens the possibility to simulate dephasing of any physical system and study fundamental questions on open quantum systems.

arXiv:1712.08071Nature CommunicationsAug 21, 201860 citations

Observation of interaction-induced asymmetric chiral currents in a synthetic zigzag ladder

Hongxing Zhao, Huiying Du, Yunfei Wang +8 more

Engineering artificial gauge fields in synthetic lattices offers an efficient avenue for exploring topological states in cold atomic physics and photonics in recent years. Interactions between the system constituents in synthetic dimensions become long ranged, and can induce more striking features. Here, we report the experimental observation of asymmetric chiral currents induced by interactions in a synthetic zigzag ladder with tunable staggered flux, based on the laser-driven coupling of discrete momentum states of ultracold $^{133}\mathrm{Cs}$ atoms. We observe that the staggered flux induces the symmetric chiral dynamics along two legs of the zigzag ladder in a noninteracting regime. However, the flux-dependent chiral currents along the two legs become asymmetric with increasing interactions, and the chiral trajectory is changed dramatically under strong interactions. Our finding opens the way for future exploration of exotic dynamics dictated by an interplay of inhomogeneous gauge fields and interactions in synthetic lattices.Engineering artificial gauge fields in synthetic lattices offers an efficient avenue for exploring topological states in cold atomic physics and photonics in recent years. Interactions between the system constituents in synthetic dimensions become long ranged, and can induce more striking features. Here, we report the experimental observation of asymmetric chiral currents induced by interactions in a synthetic zigzag ladder with tunable staggered flux, based on the laser-driven coupling of discrete momentum states of ultracold $^{133}\mathrm{Cs}$ atoms. We observe that the staggered flux induces the symmetric chiral dynamics along two legs of the zigzag ladder in a noninteracting regime. However, the flux-dependent chiral currents along the two legs become asymmetric with increasing interactions, and the chiral trajectory is changed dramatically under strong interactions. Our finding opens the way for future exploration of exotic dynamics dictated by an interplay of inhomogeneous gauge fields and interactions in synthetic lattices.

Physical Review AJul 18, 20252 citations

^{133}\mathrm{Cs}

atoms. We observe that the staggered flux induces the symmetric chiral dynamics along two legs of the zigzag ladder in a noninteracting regime. However, the flux-dependent chiral currents along the two legs become asymmetric with increasing interactions, and the chiral trajectory is changed dramatically under strong interactions. Our finding opens the way for future exploration of exotic dynamics dictated by an interplay of inhomogeneous gauge fields and interactions in synthetic lattices.