Starting from the geometric description of quantum systems, we propose a novel approach to time-independent dissipative quantum processes according to which energy is dissipated but the coherence of the states is preserved. Our proposal consists of extending the standard symplectic picture of quantum mechanics to a contact manifold and then obtaining dissipation by using appropriate contact Hamiltonian dynamics. We work out the case of finite-level systems for which it is shown, by means of the corresponding contact master equation, that the resulting dynamics constitute a viable alternative candidate for the description of this subclass of dissipative quantum systems. As a concrete application, motivated by recent experimental observations, we describe quantum decays in a 2-level system as coherent and continuous processes.
Starting from the geometric description of quantum systems, we propose a novel approach to time-independent dissipative quantum processes according to which energy is dissipated but the coherence of the states is preserved. Our proposal consists of extending the standard symplectic picture of quantum mechanics to a contact manifold and then obtaining dissipation by using appropriate contact Hamiltonian dynamics. We work out the case of finite-level systems for which it is shown, by means of the corresponding contact master equation, that the resulting dynamics constitute a viable alternative candidate for the description of this subclass of dissipative quantum systems. As a concrete application, motivated by recent experimental observations, we describe quantum decays in a 2-level system as coherent and continuous processes.
Motivated by a geometric decomposition of the vector field associated with the Gorini-Kossakowski-Lindblad-Sudarshan (GKLS) equation for finite-level open quantum systems, we propose a generalization of the recently introduced contact Hamiltonian systems for the description of dissipative-like dynamical systems in the context of (non-necessarily exact) contact manifolds. In particular, we show how this class of dynamical systems naturally emerges in the context of Lagrangian Mechanics and in the case of nonlinear evolutions on the space of pure states of a finite-level quantum system.
We develop a framework to analyze the dynamics of a finite-dimensional quantum system S in contact with a reservoir R . The full, interacting SR dynamics is unitary. The reservoir has a stationary state but otherwise dissipative dynamics. We identify a main part of the full dynamics, which approximates it for small values of the SR coupling constant, uniformly for all times t≥0 . The main part consists of explicit oscillating and decaying parts. We show that the reduced system evolution is Markovian for all times. The technical novelty is a detailed analysis of the link between the dynamics and the spectral properties of the generator of the SR dynamics, based on Mourre theory. We allow for SR interactions with little regularity, meaning that the decay of the reservoir correlation function only needs to be polynomial in time, improving on the previously required exponential decay.In this work we distill the structural and technical ingredients causing the characteristic features of oscillation and decay of the SR dynamics. In the companion paper [27] we apply the formalism to the concrete case of an N -level system linearly coupled to a spatially infinitely extended thermal bath of non-interacting Bosons.
Quantum mechanics is conventionally formulated in terms of complex Hilbert spaces, linear operators, and the Schrödinger equation. Although geometric structures play an increasingly important role in modern formulations of quantum theory, the wavefunction itself is generally regarded as a fundamental object. In this work, we investigate an alternative formulation in which the fundamental object is a coherence coordinate , where Omega represents radial coherence and Theta represents phase coherence associated with geometric transport. Starting from three assumptions—a coherence coordinate, a probability density generated by radial coherence, and a geometric Hamiltonian—we reconstruct the continuity equation, the quantum Hamilton–Jacobi equation, and ultimately the Schrödinger equation. Within this framework, the wavefunction appears as a derived quantity, while Hilbert spaces emerge naturally as spaces of square-integrable functions on a coherence manifold. The resulting construction establishes a differential-geometric representation of quantum mechanics and provides a common geometric language connecting quantum states, probability flow, geometric phases, holonomies, and gauge transport.
We propose an ontological reformulation of quantum mechanics based on a fundamental distinction between static states and dissipative processes. Static states are time‑independent configurations of charge or matter density, devoid of internal dynamics. Dissipative processes, in contrast, involve real changes in density, energy loss, and irreversibility. This distinction enables a coherent and realistic reinterpretation of electronic orbitals, spin, atomic transitions, nuclear decay, tunneling, and entanglement. We show that every emission or absorption event requires dissipation, and that in an ensemble of excited systems the number of ideal observable transitions is always smaller than the number of initially excited systems. We extend the framework to nuclear structure and quantum correlations, highlighting the conceptual continuity of the theory and its compatibility with the thermodynamics of information.
This work proposes a conceptual and ontological reformulation of classical dynamics, thermodynamics, and quantum mechanics based on a single postulate: dissipation is a fundamental property of all physical processes. Traditional dynamics relies on the idealization of isolated, reversible systems, yet no real physical system satisfies such conditions. By introducing an intrinsic dissipative energy term into the equations of motion, we suggest that dissipation entails an irreversible loss of physical information, from which a classical uncertainty principle naturally follows. Stationary states are reinterpreted as zero‑dissipation configurations, lacking internal temporal evolution, thereby offering an ontological basis for quantization, non‑locality, and the Heisenberg uncertainty principle. Quantum mechanics can thus be viewed as the mathematical description of these stationary states and of the dissipative transitions connecting them. The framework is conceptually consistent with fluctuation‑dissipation theory, open‑system quantum dynamics, decoherence theory, and relaxation phenomena in NMR spectroscopy. Several experimental proposals are outlined to discriminate this ontological model from both classical mechanics and standard quantum mechanics.
Recently, it has been realized that dissipative processes can be harnessed and exploited to the end of coherent quantum control and information processing. In this spirit, we consider strongly dissipative quantum systems admitting a nontrivial manifold of steady states. We show how one can enact adiabatic coherent unitary manipulations, e.g., quantum logical gates, inside this steady-state manifold by adding a weak, time-rescaled, Hamiltonian term into the system's Liouvillian. The effective long-time dynamics is governed by a projected Hamiltonian which results from the interplay between the weak unitary control and the fast relaxation process. The leakage outside the steady-state manifold entailed by the Hamiltonian term is suppressed by an environment-induced symmetrization of the dynamics. We present applications to quantum-computation in decoherence-free subspaces and noiseless subsystems and numerical analysis of nonadiabatic errors.