Non-Markovian quantum dynamics in physical systems: description and control

Quantum collision models are pivotal for simulating open quantum systems, yet lack comprehensive error certification. The authors analytically derive Markovian and non-Markovian collision models from chain mapping techniques, identifying a critical error source, thus elevating collision models to numerically exact methods and enhancing their reliability across quantum simulations.

The development of fast and efficient quantum batteries is crucial for the prospects of quantum technologies. In this work the authors have shown that both requirements are accomplished in the paradigmatic model of a harmonic oscillator strongly coupled to a highly non-Markovian thermal reservoir.

Combining standard quantum benchmarking techniques with a physics-inspired supervised machine learning algorithm, the authors efficiently and accurately predict the functioning of a superconducting qubit in the presence of complex noise. The proposed approach opens a path towards a better control of current quantum devices.

It is generally believed that quantum tunneling cannot occur when the distance is larger than the particle’s wavelength. This paper reveals that a long-range quantum tunneling of the atom to the remote trapping potentials mediated by its emitted matter wave occurs as long as bound states are present in the energy spectrum of the total system formed by the atom and its matter-wave.

Quantum metrology, a powerful paradigm for surpassing classical measurement precision, has been extensively studied for Markovian noise, while most practical physical processes obey non-Markovian dynamics. In this paper, the authors propose control-enhanced quantum metrology schemes to counteract non-Markovian noise and experimentally verify their efficacy.

Quantum Speed Limit (QSL) is a lower bound on the time evolution for quantum systems. Still, experimental studies for open systems are few due to the lack of control over their environment’s interaction. The authors control the qubitreservoir interaction in an ensemble of chloroform molecules, observing crossovers between different QSLs.

The description of open systems featuring anti parity-time symmetry builds on the assumption that the system does not retain memory. Here, the authors propose a system with anti-PT-symmetry where a single time-delay encodes the retention of memory, and experimentally demonstrate it by coupling two time-delay semiconductor lasers.

Quantifying, controlling, and correcting noise related errors is one of the current challenges in quantum computing. Here, the authors study the time dependence of the relaxation of a stationary state simulated on a quantum computer, and show that such spectroscopic signature is unique and can be used to characterize the noise on individual quantum computers.