Quantum energy teleportation (QET) is a protocol that unlocks the extraction of local energy and has been thought to fundamentally require classical communication (CC), since Bob must normally learn Alice's measurement outcome to perform the proper conditional operation (CO).In this work, we demonstrate that CC itself can be removed for the purpose of QET: When Bob's local operation is implemented through a weak coupling to an auxiliary qubit, the interaction naturally adapts to Alice's post-measurement state, thereby realizing the necessary CO without any classical message.This establishes a CC-free form of QET, which broadens its conceptual scope and suggests practical applications such as indirect external control for charging of quantum batteries.
Quantum energy teleportation (QET) is a protocol that unlocks the extraction of local energy and has been thought to fundamentally require classical communication (CC), since Bob must normally learn Alice's measurement outcome to perform the proper conditional operation (CO).In this work, we demonstrate that CC itself can be removed for the purpose of QET: When Bob's local operation is implemented through a weak coupling to an auxiliary qubit, the interaction naturally adapts to Alice's post-measurement state, thereby realizing the necessary CO without any classical message.This establishes a CC-free form of QET, which broadens its conceptual scope and suggests practical applications such as indirect external control for charging of quantum batteries.
In this work, we explore quantum energy teleportation (QET) protocols, focusing on their behavior at finite temperatures , in ground and excited states. We analyze the role of entanglement as a resource for QET, particularly in thermal states, and compare the performance of QET across these initial states. We then introduce a method to extract ground-state energy through a protocol that employs only quantum measurements, local operations, and classical communication (LOCC), without requiring the ground state to be quantum correlated either through entanglement or quantum discord. To illustrate this, we propose a minimal model comprising two interacting qubits. These findings indicate that, in addition to the established QET framework where quantum correlation serves as a resource, it is possible to extract energy from an product ground state. This broadens the scope of QET's applicability across diverse quantum systems.
Quantum energy teleportation (QET) has been proposed to overcome the restrictions of strong local passivity (SLP) and to facilitate energy transfer in quantum systems. Traditionally, QET has only been considered under strict constraints, including the requirements that the initial state be the ground state of an interacting Hamiltonian, that Alice's measurement commute with the interaction terms, and that entanglement be present. These constraints have significantly limited the broader applicability of QET protocols. In this work, we demonstrate that SLP can arise beyond these conventional constraints, establishing the necessity of QET in a wider range of scenarios for local energy extraction. This leads to a more flexible and generalized framework for QET. Furthermore, we introduce the concept of a "local effective Hamiltonian," which eliminates the need for optimization techniques in determining Bob's optimal energy extraction in QET protocols. As an additional advantage, the amount of energy that can be extracted using our new protocol is amplified to be 7.2 times higher than that of the original protocol. These advancements enhance our understanding of QET and extend its broader applications to quantum technologies. To support our findings, we implement the protocol on quantum hardware, confirming its theoretical validity and experimental feasibility.
Quantum energy teleportation (QET) is an energy extraction protocol via local operation and classical communication (LOCC). In this paper, we analyze QET with the correlation matrix and find the essence of QET is a quantum steering process. We propose an extended QET called strong QET protocol and define the QET passive state, which shows that quantum correlation is not a sufficient condition for QET. We also compare QET in noisy channels with direct energy extraction schemes, which indicates the advantage of our method in dealing with quantum operations. Furthermore, we extend the method to the N-qubit QET and give numerical examples.
Quantum energy teleportation (QET) is a protocol that enables the extraction of positive energy from a local subsystem by exploiting ground-state entanglement and classical communication, without any physical carrier transporting energy between distant parties. In this work, we propose and analyze a QET protocol implemented in strongly driven atomic systems subjected to intense classical fields. We model a pair of interacting two-level atoms (or effective few-level systems) driven by a strong, time-dependent field and coupled via dipole–dipole or mediated interactions. The strong field creates a nontrivial, Floquet-engineered energy landscape and modifies the structure of ground-state and steady-state correlations. Within this setting, we construct local energy density operators and identify regimes in which negative local energy densities are dynamically generated and can be accessed via local measurements. We then formulate a QET protocol in which Alice performs a local measurement on her strongly driven atom, injects energy into the system, and sends the classical outcome to Bob, who performs a conditional local unitary on his distant atom to extract positive energy from the strongly driven environment. We derive explicit expressions for the teleported energy and analyze its dependence on driving strength, detuning, atom–atom coupling, and measurement parameters. Our results demonstrate that strong-field driving can enhance the amount of teleported power , extend the QET operating range to non-equilibrium Floquet regimes, and provide a feasible route toward realizing QET in tabletop atomic platforms driven by intense laser fields.
We demonstrate that charge teleportation serves as a superior observable for Quantum Energy Teleportation (QET)-based cryptographic primitives. While following the LOCC protocol structure of earlier proposals, we show that decoding key bits via local charge rather than energy provides exact bit symmetry and enhanced robustness: by Local Operations and Classical Communication (LOCC) on an entangled many-body ground state, Alice's one-bit choice steers the sign of a local charge shift at Bob, which directly encodes the key bit. Relative to energy teleportation schemes, the charge signal is bit-symmetric, measured in a single basis, and markedly more robust to realistic noise and model imperfections. We instantiate the protocol on transverse-field Ising models, star-coupled and one-dimensional chain, obtain closed-form results for two qubits, and for larger systems confirm performance via exact diagonalization, circuit-level simulations, and a proof-of-principle hardware run. We quantify resilience to classical bit flips and local quantum noise, identifying regimes where sign integrity, and hence key correctness, is preserved. These results position charge teleportation as a practical, low-rate QKD primitive compatible with near-term platforms.
Quantum energy teleportation (QET) is, from the operational viewpoint of distant protocol users, energy transportation via local operations and classical communication. QET has various links to fundamental research fields including black-hole physics, the quantum theory of Maxwell's demon, and quantum entanglement in condensed-matter physics. However, the energy that has been extracted using a previous QET protocol is limited by the distance between two protocol users; the upper bound of the energy being inversely proportional to the distance. In this paper, we prove that introducing squeezed vacuum states with local vacuum regions between the two protocol users overcomes this limitation, allowing energy teleportation over practical distances.