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arXiv:2601.20287

Fingerprints of classical memory in quantum hysteresis

Francesco Caravelli

quant-phcond-mat.otherSubmitted Jan 28, 2026• Announced Jan 29, 2026• 0 citations
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Abstract

We present a simple framework for classical and quantum ``memory'' in which the Hamiltonian at time $t$ depends on past values of a control Hamiltonian through a causal kernel. This structure naturally describes finite-bandwidth or filtered control channels and provides a clean way to distinguish between memory in the control and genuine non-Markovian dynamics of the state. We focus on models where $H(t)=H_0+\int_{-\infty}^{t}K(t-s)\,H_1(s)\,ds$, and illustrate the framework on single-qubit examples such as $H(t)=σ_z+Φ(t)σ_x$ with $Φ(t)=\int_{-\infty}^{t}K(t-s)\,u(s)\,ds$. We derive basic properties of such dynamics, discuss conditions for unitarity, give an equivalent time-local description for exponential kernels, and show explicitly how hysteresis arises in the response of a driven qubit.

Comments
22 pages double column; 26 pages appendix

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Standard quantum mechanics assumes that the temporal evolution of a closed quantum system is entirely governed by its instantaneous state and Hamiltonian, following a strictly Markovian paradigm where future dynamics depend solely on the present. This paper introduces the theoretical framework of Quantum-State Inertial Memory (QSIM), which challenges this instantaneous assumption by postulating that the rate of change of a quantum state depends intrinsically on its historical trajectory through a self-induced memory response kernel. By formulating a generalized integro-differential evolution equation where the velocity of the state vector |psi(t)> incorporates past configurations |psi(t')> weighted by a memory kernel K(t - t'), we distinguish QSIM from conventional environmental decoherence and open-system memory models. We systematically examine the mathematical properties of these historical response kernels, demonstrate how quantum systems sharing identical instantaneous states can exhibit divergent future trajectories due to path dependence, and explore the foundational implications for treating quantum states as objects possessing internal temporal inertia.
We introduce a minimal non-Markovian extension of a scalar field model by including a temporal memory kernel with finite relaxation time. The resulting dynamics can be reformulated as a local system with an additional internal degree of freedom. We show that this modification induces history-dependent corrections to quantum tunneling probabilities, leading to a hysteresis effect. An order-of-magnitude estimate suggests that the effect may be observable in tunneling-dominated systems such as nuclear decay.
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The reduced description of the quantum dynamic processes in the condensed phase environment leads to the equation of motion with a memory kernel. Such a memory effect, termed non-Markovianity, presents more complex dynamics compared to its memoryless or Markovian counterpart, and many chemical systems have been demonstrated through numerical simulations to exhibit non-Markovian quantum dynamics. Explicitly how the memory impacts the dynamic process remains largely unexplored. In this work, we focus on ways to separate the non-Markovian contributions from the dynamics and study the non-Markovian effects. Specifically, we developed a rigorous procedure for mapping the exact non-Markovian quantum propagator to the Lindblad form. Consequently, it allows us to extract the negative decay rate from the Lindbladian that is the signature of the non-Markovianity. By including or excluding the negative rate in the time evolution, we can decisively pinpoint the influence of non-Markovianity on the system's properties such as coherence, entanglement, and equilibrium state distribution. The understanding of such memory effects on the dynamic process suggests the possibility of leveraging non-Markovianity for quantum control.
We propose an effective field-theoretic framework for open quantum systems in which decoherence dynamics are influenced by an auxiliary scalar field acting as an informational memory degree of freedom. This additional field induces intrinsically non-Markovian behavior, leading to structured noise spectra and deviations from standard exponential decay. The resulting reduced dynamics are governed by a non-local memory kernel, capturing temporal correlations beyond conventional approaches. We show that the model predicts oscillatory modulations in coherence decay and provides improved fits to simulated qubit data compared to both exponential and stretched-exponential models. The framework also reproduces nontrivial residual structures and spectral features that are not accounted for in standard decoherence theories. To test these predictions, we propose an experimental protocol using superconducting qubits, where systems initialized under identical environmental conditions but with different controlled histories exhibit distinguishable decoherence dynamics. This history dependence offers a potential experimental signature of the proposed mechanism. Overall, this work provides a phenomenological extension of decoherence theory and highlights the role of memory effects and informational degrees of freedom in open quantum systems, suggesting new directions for both theoretical and experimental investigation.