Realistic work extraction from many-body quantum batteries must be local. However, only a small fraction of energy eigenstates of a generic many-body system, called scars, can support local extraction. The remaining bulk is useless for the task due to the eigenstate thermalization hypothesis. Here we devise a universal low-complexity protocol that steers any initial state towards exactly one scar---representing a charged state of the battery---from which a macroscopic amount of work can be extracted using local unitary operations. This is achieved by leveraging the nontrivial interplay of engineered dissipation and continuous indirect measurement that, in addition, leads to enhanced stability and charging speed compared to any other strategy using these processes independently. Moreover, the protocol works directly on the hardware level, in that it requires no simulation or suppression of interactions between subsystems. Our construction thereby enables macroscopic charge storage in steady states of generic nonintegrable many-body systems indefinitely, from which a reliable stream of work can be extracted via purely local means.
We propose an autonomous quantum-battery protocol based on dissipatively selected quantum many-body scars. Using an embedding-type spin chain with an exact scar tower and a generalized interacting
J1--
J2 chain, we show that engineered local bond dissipation can drive the system from a passive state into a high-energy scar-supported manifold with large extractable work. The resulting charged states exhibit single-copy ergotropy close to the entropy-matched thermodynamic work bound while retaining the coherent structure associated with the scar ladder. Because the ideal scar manifold also supports nondecaying peripheral modes, we introduce weak local dephasing to obtain a stable charging protocol and find a broad regime in which the charging time is reduced without substantially degrading the stored work. Finally, an explicit scar-breaking perturbation produces a correlated loss of scar support and extractable work, demonstrating that the favorable battery performance is tied to the nonthermal scar structure rather than merely to the preparation of a generic excited state. Our results establish dissipatively stabilized many-body scars as a promising resource for autonomous and robust quantum energy storage.
Quantum hardware increasingly relies on energy reserves that can later be converted into useful work; yet, most battery-like proposals demand coherent drives or engineered non-equilibrium resources, limiting practicality in noisy settings. We develop an autonomous charging paradigm in which an ensemble of identical two-level units, collectively coupled to a thermal environment, acquires work capacity without any external control. The common bath mediates interference between emission and absorption pathways, steering the many-body state away from passivity and into a steady regime with nonzero extractable work. The full charging dynamics and closed-form expressions are obtained for the steady-state, showing favorable scaling with the number of cells that approach the many-body optimum. We show that the mechanism is robust to local noise: under a convex mixture of collective and local dissipation, non-zero steady-state ergotropy persists, exhibits counterintuitive finite-temperature optima, and remains operative when the collective channel is comparable to or stronger than the local one. We show that environmental fluctuations can be harnessed to realize drive-free, scalable quantum batteries compatible with circuit- and cavity-QED platforms. Used as local work buffers, such batteries could potentially enable rapid ancilla reset, bias dissipative stabilizer pumps, and reduce syndrome-extraction overhead in fault-tolerant quantum computing.
Quantum many-body scars break ergodicity and evade thermalization, resulting in sub-volume law entanglement entropy even with high energy density. While their quantum correlations and entanglement have been elaborated previously, their capacity in storing extractable energy, quantified by the notion ergotropy, remains an open question. Here we focus on the representative PXP model, and unveil the extensive ergotropy scaling of a family of states interpolating between quantum many-body scars and thermal states, the latter of which are known to be passive with vanishing ergotropy in the thermodynamic limit. A phenomenological relation between ergotropy and entanglement is uncovered, which generalizes the existing free fermion integrable results to an interacting scenario. The ergotropy in a dynamical protocol shows that a reset with a global uniform coherent rotation can inject extractable energy, as a proof of principle way to charge a quantum "battery". Our protocol is tailored for near term Rydberg neutral atoms array, while also being feasible for other quantum processors. Our results establish that quantum many-body scars, despite the tiny fraction of the Hilbert space they occupy, can be efficiently exploited for storing extractable energy, and "scarring" a many-body system as a promising route for engineering quantum many-body battery.
In this dissertation, we investigate the charging and discharging dynamics of a quantum battery composed of a collectively driven ensemble of
N identical two level systems coupled to a structured electromagnetic environment. The system is described using collective angular momentum operators in the Dicke basis, which provides a compact and physically transparent framework for analyzing collective light-matter interactions. Rather than treating dissipation as an unwanted source of loss, we explicitly use it as a mechanism for energy storage and work extraction. Starting from a coherently driven ensemble coupled to common reservoirs, we derive a master equation in Lindblad form under the Born-Markov and secular approximations. In the dressed-state basis, spontaneous emission induces irreversible transitions that can increase the energy stored in the bare basis. We obtain analytic expressions for the steady state, including the stored energy and the ergotropy, and identify parameter regimes where substantial collective coherence is generated. A central result of this work is the demonstration that, in the extensive regime where the total energy scales linearly with
N and relative fluctuations vanish, the charging power scales as
N2. This quadratic enhancement scaling exceeds the
N3/2 limit previously established for purely Hamiltonian charging protocols of noninteracting Dicke batteries in the same regime. We show that this enhancement is consistent with quantum speed limits for open-system dynamics and originates from collectively enhanced dissipative processes analogous to superradiance. We further analyze the extraction process and show that the charged steady state stores not only energy but a macroscopic collective dipole moment. This coherence enables rapid energy release through either collective spontaneous emission or stimulated emission driven by an external coherent field. In the appropriate large
N extensive regime, the stored energy can become fully extractable in principle, and the discharging power also exhibits
N2 scaling. These results establish that dissipative protocols can provide a genuine collective advantage over Hamiltonian schemes in the extensive regime, while also highlighting the interplay between enhanced collective power and the conditions required to achieve high extractable energy.
Quantum many-body scars are nonthermal excited eigenstates of nonintegrable Hamiltonians, which could support coherent revival dynamics from special initial states when scars form an equally spaced tower in the energy spectrum. For open quantum systems, engineering many-body scarred dynamics by a controlled coupling to the environment remains largely unexplored. Here, we provide a general framework to exactly embed quantum many-body scars into the decoherence-free subspaces of Lindblad master equations. The dissipative scarred dynamics manifest persistent periodic oscillations for generic initial states, and can be practically utilized to prepare scar states with potential quantum metrology applications. We construct the Liouvillian dissipators with the local projectors that annihilate the whole scar towers, and utilize the Hamiltonian part to rotate the undesired states out of the null space of dissipators. We demonstrate our protocol through several typical models hosting many-body scar towers and propose an experimental scheme to observe the dissipative scarred dynamics based on digital quantum simulations and resetting ancilla qubits.
Suppressing coherent energy backflow while maintaining extractable energy in a stable nonequilibrium state remains a central challenge for quantum energy storage. Here, we introduce a reservoir-engineered dual-charger quantum battery architecture, in which nonequilibrium dissipation is exploited as a control resource to stabilize useful stored energy. A hot-reservoir-coupled driver supplies excitations, while a cold-reservoir-coupled cache biases the resonant three-body transition toward charging and suppresses the dressed-state coherences responsible for energy backflow. This mechanism establishes a population-inverted steady state with finite ergotropy and converts reversible charger--battery exchange into persistent energy storage. For uniformly spaced multilevel batteries, we show that the stored energy and ergotropy scale approximately linearly with the number of accessible levels, while the stored-energy utilization approaches unity. The accompanying stationary heat current provides a thermodynamic signature of the charging regime. Our results demonstrate dissipation engineering as a strategy for achieving stable and scalable quantum energy storage beyond transient coherent charging protocols.