Chiral Squeezing Turns Quantum Noise Into Battery Charge

A new quantum-battery proposal asks a provocative question: what if the noisy fluctuations that normally make amplifiers thermodynamically messy could be steered, squeezed and stored as mostly extractable energy?

The paper, “Charging Quantum Batteries with Chiral Squeezing”, was submitted to arXiv on June 15, 2026 by Borhan Ahmadi, André H. A. Malavazi, Janine Splettstoesser, Paweł Horodecki and Lei Du. It proposes a charger built from a driven bosonic Kitaev chain, a one-dimensional network in which ordinary hopping between sites is combined with parametric pumping that creates or annihilates excitations in pairs. In the authors’ model, this active chain converts passive input fluctuations into ordered, non-passive states at two battery modes coupled to the chain ends.

That is a subtle but important shift in how quantum batteries are usually discussed. Many battery papers ask how much energy can be stored, how quickly it can be delivered, or how collective quantum effects such as entanglement can speed charging. This new work focuses on a harder thermodynamic requirement: Can the energy that lands in the battery be extracted as useful work, rather than appearing mainly as noisy heat-like excitation?

The central idea is not simply to amplify a signal. It is to use a time-driven quantum lattice so that amplified fluctuations arrive in a structured, low-entropy form with high ergotropy.

Why ordinary amplification is not enough

Quantum amplifiers are familiar tools in superconducting circuits, microwave photonics and precision measurement. They can boost weak signals, but amplification almost always brings a noise bill. A phase-preserving amplifier, for example, must add fluctuations required by quantum mechanics. If a quantum battery is charged by a generic noisy amplifier, the total energy may rise while the fraction available as clean work remains disappointing.

The relevant concept here is ergotropy: the maximum work extractable from a quantum state by unitary operations. A battery can be energetic but passive, meaning no work can be extracted without additional resources because the energy is distributed like a thermal state. The valuable state is non-passive: ordered enough that a suitable operation can draw work from it.

Ahmadi and colleagues frame this as a signal-to-noise problem. A charger that merely increases energy variance is not enough. A useful charger should raise extractable energy while keeping the intrinsic energy fluctuations under control. Their reported benchmark is a work-like signal-to-noise ratio near unity at the optimal charging time, even with thermal noise and moderate disorder that preserves the chain’s symmetry.

The bosonic Kitaev chain as a directional charger

The charger is based on a uniform chain of 2N + 1 bosonic sites. Neighboring sites are connected by hopping with amplitude h, while a parametric pump contributes two-particle pairing with amplitude Δ. In a rotating frame, the chain decomposes into two Hatano-Nelson-like quadrature chains: the position-like x quadrature prefers one direction, while the momentum-like p quadrature prefers the opposite direction.

For a smart non-specialist, the image is a conveyor belt that separates two components of a quantum fluctuation. One quadrature is pushed toward the right end; the orthogonal quadrature is pushed toward the left. The two ends are coupled to battery modes. A short coherent pulse enters the center, but the paper finds that the coherent part is not the main energy carrier. Because the pulse is finite and dissipation accumulates across the chain, its direct stored-energy contribution remains small.

The more surprising result is that the fluctuation sector dominates. Fluctuations are continuously injected through the driven-dissipative chain. The parametric pump amplifies them, the chiral transport separates their quadratures, and the end batteries receive squeezed states that are not merely hot. In the authors’ words, the active bosonic Kitaev dynamics converts originally passive fluctuations into ordered, non-passive battery energies.

Floquet engineering without saying “Floquet” in every equation

The paper’s model is written as a driven rotating-frame Hamiltonian rather than a simple static lattice. The pairing term is generated by an external parametric pump; it is an active, time-dependent resource. That places the proposal squarely in the broader Floquet-engineering family: periodic control is not a nuisance, but the mechanism that creates effective couplings, directionality and amplification unavailable in an undriven passive chain.

This matters for energy science because Floquet control is often criticized for heating. The chiral-squeezing battery turns the conversation around. Instead of asking only how to suppress all drive-induced fluctuations, it asks how a driven system can process fluctuations into a useful resource. The drive still costs energy and must be counted in a full device-level thermodynamic budget. But the proposal suggests that a properly structured drive can convert noise-like inputs into states with a large extractable component.

The authors also identify an important operating regime. For open boundaries, the bosonic Kitaev chain is dynamically stable when |h| > |Δ|. When the parametric pump overwhelms hopping, the system becomes unstable and controlled wave transport breaks down. Practical devices would therefore need to operate below this instability threshold while still obtaining enough squeezing to be useful.

Robustness: good disorder and bad disorder

No laboratory chain is perfectly uniform. The paper tests two forms of static disorder: hopping disorder and pump-disorder fluctuations. For a chain half-length N = 5, the authors sample 50 random realizations and find that the work-like signal-to-noise ratio remains close to the disorder-free value across a broad range of disorder strengths.

The reason is symmetry. Hopping and pump disorder preserve the bosonic-Kitaev-chain structure that keeps the x and p quadrature sectors from mixing. The chiral dynamics remains protected by the chain’s point-gap topology, so moderate imperfections do not immediately destroy the charging protocol.

The caveat is equally important. Random on-site detunings are more dangerous because they mix the two quadratures. Strong detuning disorder can degrade chirality and even trigger uncontrolled amplification. The practical design lesson is clear: tolerances are not only about making every component identical. They are about preserving the symmetry class that makes the energy-routing mechanism work.

For quantum-energy hardware, robustness means more than “the signal survives.” It means the extractable-work structure survives the imperfections that real devices inevitably contain.

Why experimental platforms are plausible

The proposal is theoretical, but it is not detached from hardware. The authors point to parametric superconducting resonators and optomechanical arrays as candidate platforms. That is significant because the bosonic Kitaev chain has recently moved from a mathematical model into experimentally relevant systems. The paper cites, among others, a 2024 Nature Communications study on quantum simulation of the bosonic Kitaev chain by Busnaina and collaborators, and a 2024 Nature paper by Slim and collaborators reporting an optomechanical realization.

Superconducting circuits are attractive because parametric pumping, microwave squeezing and engineered dissipation are already central tools in the field. Optomechanical platforms are attractive because light-mechanical interactions can implement non-Hermitian and direction-sensitive dynamics with tunable losses. Neither platform would make a power-grid battery. The point is more foundational: they could test whether a driven quantum network can store fluctuation energy as ergotropy, not just as heat.

Connections to beyond-Carnot thermodynamics

Beyond-Carnot research is not about violating Carnot’s theorem. It is about identifying non-thermal resources—coherence, squeezing, measurement, feedback, correlations, non-equilibrium reservoirs and time-dependent control—and accounting for them honestly. Chiral squeezing sits directly in that resource-theory landscape. The external pump supplies work. The driven lattice reshapes fluctuations. The batteries receive non-passive states. The thermodynamic question becomes: after including the pump cost, losses and extraction operation, when does the architecture outperform a simpler charger?

That question is still open. The paper establishes a mechanism and useful figures of merit, not a finished engine. A complete device analysis would need to include how the parametric drive is generated, how the batteries are disconnected at the optimal time, how the stored ergotropy is extracted, and how repeated charging cycles behave under realistic control errors.

Still, the conceptual contribution is valuable. It reframes fluctuations from a nuisance into a possible fuel stream for quantum storage. In a world where quantum devices are inherently noisy, designs that sort, squeeze and route noise may be more realistic than designs that require noise to disappear.

What to watch next

Three follow-up directions stand out. First, the proposal needs platform-specific simulations that include real pump inefficiencies and readout constraints. Second, an experiment should measure not only stored energy but ergotropy or an operational proxy for extractable work. Third, researchers should ask whether related Floquet or parametrically driven lattices can achieve the same fluctuation-to-work conversion with fewer components, shorter chains or stronger protection against detuning disorder.

For floquet.ca’s quantum-energy roadmap, this is a timely result. It links Floquet-style active control, non-Hermitian directional transport, squeezing and quantum batteries in one architecture. The long-term promise is not that noise magically becomes free energy. It is that the microscopic structure of driven quantum noise may be engineered well enough to make some of it useful.

Sources and further reading

Primary paper: Borhan Ahmadi, André H. A. Malavazi, Janine Splettstoesser, Paweł Horodecki & Lei Du, “Charging Quantum Batteries with Chiral Squeezing,” arXiv: 2606.16764 (submitted June 15, 2026).

Foundational concepts: A. E. Allahverdyan, R. Balian & Th. M. Nieuwenhuizen, “Maximal work extraction from finite quantum systems,” Europhysics Letters 67, 565 (2004), DOI: 10.1209/epl/i2004-10101-2; N. Hatano & D. R. Nelson, “Localization Transitions in Non-Hermitian Quantum Mechanics,” Physical Review Letters 77, 570 (1996), DOI: 10.1103/PhysRevLett.77.570.

Experimental context cited by the authors: J. H. Busnaina and collaborators, “Quantum simulation of the bosonic Kitaev chain,” Nature Communications 15 (2024); J. J. Slim and collaborators, “Optomechanical realization of the bosonic Kitaev chain,” Nature 627, 767 (2024).