Quantum Energy Teleportation provides a testbed for modern ideas involving the interplay between quantum correlations and energy in the quantum thermodynamical regime. In this work, we provide a new class of Quantum Energy Teleportation protocols optimized for harnessing maximal amounts of correlations between subsystems. We also construct new measurement protocols for quantum fields which provide significant improvements for entanglement harvesting. Finally, we construct an efficient formalism for computing changes in energy due to localized interactions in quantum field theory.
Quantum Energy Teleportation provides a testbed for modern ideas involving the interplay between quantum correlations and energy in the quantum thermodynamical regime. In this work, we provide a new class of Quantum Energy Teleportation protocols optimized for harnessing maximal amounts of correlations between subsystems. We also construct new measurement protocols for quantum fields which provide significant improvements for entanglement harvesting. Finally, we construct an efficient formalism for computing changes in energy due to localized interactions in quantum field theory.
Quantum energy teleportation (QET) is a quantum feedback protocol in which local measurements, classical communication, and preexisting entanglement enable the extraction of energy at a distant site, without transporting physical energy carriers. Originally conceived as a theoretical manifestation of Maxwell’s demon, QET has developed into a versatile tool for probing quantum correlations, diagnosing phase transitions, and powering emergent quantum thermodynamic technologies. This brief review provides a pedagogical introduction to the theoretical foundations and recent developments of QET, including quantum operations, entropic and fidelity-based bounds, and resource analyses involving quantum discord. Additionally, recent experimental realizations on superconducting quantum computers are revisited.
Quantum field theory can be a new medium for communication through quantum energy teleportation. We perform a demonstration of quantum energy teleportation with a relativistic fermionic field theory of self-coupled fermions, called the massive Thirring model. Our results reveal that there is a close relationship between the amount of energy teleported and the phase diagram of the theory. In particular, we show that the teleported energy peaks near the phase transition points. Since these results are obtained by measuring the two local subsystems, the noise from the quantum computation can be considerably reduced, allowing for efficient quantum simulations. Moreover, it is a new entanglement-based method that reveals global structure through local measurements.
Quantum energy teleportation (QET) exploits the existence of correlations to enable remote energy transfer without the need for physical energy carriers between emitter and receiver. This paper presents a review of the thermodynamic foundations of QET and reviews its first experimental demonstration (performed using nuclear magnetic resonance), along with its implementation on publicly available superconducting quantum hardware. Additionally, we review an application of QET in the field of quantum thermodynamics as an efficient algorithmic cooling technique to cool down individual parts of interacting systems. Finally, we will review how QET can be employed to optimally generate exotic quantum states characterized by negative average stress–energy densities, offering a new operational approach to engineering such states that are promising in the context of semiclassical gravity.
We establish a novel quantum protocol called Timelike Quantum Energy Teleportation (TQET) between two separated parties A and B, designed for transporting quantum energy across spacetime. The amount of energy gained through TQET is always greater than or equal to that obtained via natural time evolution for any spin chain where A and B are distinguishable. This protocol uses temporal and spatial quantum correlations between agents separated by space and time. The energy supplier injects energy into the system by measuring the ground state of a many-body system that evolves over time, while the distant recipient performs a conditional operation using feedback from the supplier. When Bob acts immediately after receiving Alice's outcome, the protocol reduces to conventional QET. We present a proof-of-concept demonstration in the Ising model using quantum simulations. TQET increases energy efficiency from approximately 3\% to around 40\%, representing over a 13-fold improvement compared to QET. Furthermore, we analyzed the relationship between entanglement in time and TQET, validating the role of temporal correlations in energy activation between agents across spacetime.
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.
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.