Motivated by anomalous nonlocal correlation in the Kitaev spin liquids, we propose a quantum energy teleportation protocol between remote partners Alice and Bob on a quantum spin model, and examine how its performance is characterized by Majorana fermions that clearly depict nonlocal correlations inherent in the model. In our model, Bob's energy extraction is activated by energy injection by Alice's projective measurement and subsequent classical communication of the measurement result. We derive two formulas: one for the maximally extracted energy by the protocol, Δ E B max , and the other for the maximum of energy reduction in a local spin system where Bob performs feedback unitary operation, Δ E B , B max . The protocol aims to extract a positive amount of the former energy distinct from the latter due to the presence of an interaction between the local system and others. We find that the extracted energy becomes positive when a nonlocal correlator defined by Majorana fermions at Alice and Bob's sites is finite. We also find that the amount of the energy reduction becomes positive when another nonlocal Majorana correlator is finite. In both formulas, the correlators appear as a result of Bob's feedback unitary operation. We find that the latter formula is equal to the upper bound of energy extraction in the second law of effective information thermodynamics. We discuss the effective information-thermodynamical aspects behind the protocol at zero temperature.
Motivated by anomalous nonlocal correlation in the Kitaev spin liquids, we propose a quantum energy teleportation protocol between remote partners Alice and Bob on a quantum spin model, and examine how its performance is characterized by Majorana fermions that clearly depict nonlocal correlations inherent in the model. In our model, Bob's energy extraction is activated by energy injection by Alice's projective measurement and subsequent classical communication of the measurement result. We derive two formulas: one for the maximally extracted energy by the protocol, Δ E B max , and the other for the maximum of energy reduction in a local spin system where Bob performs feedback unitary operation, Δ E B , B max . The protocol aims to extract a positive amount of the former energy distinct from the latter due to the presence of an interaction between the local system and others. We find that the extracted energy becomes positive when a nonlocal correlator defined by Majorana fermions at Alice and Bob's sites is finite. We also find that the amount of the energy reduction becomes positive when another nonlocal Majorana correlator is finite. In both formulas, the correlators appear as a result of Bob's feedback unitary operation. We find that the latter formula is equal to the upper bound of energy extraction in the second law of effective information thermodynamics. We discuss the effective information-thermodynamical aspects behind the protocol at zero temperature.
Energy in a multipartite quantum system appears from an operational perspective to be distributed to some extent non-locally because of correlations extant among the system's components. This non-locality allows users to transfer, in effect, locally accessible energy between sites of different system components by local operations and classical communication (LOCC). Quantum energy teleportation is a three-step LOCC protocol, accomplished without an external energy carrier, for effectively transferring energy between two physically separated, but correlated, sites. We apply this LOCC teleportation protocol to a model Heisenberg spin particle pair initially in a quantum thermal Gibbs state, making temperature an explicit parameter. We find in this setting that energy teleportation is possible at any temperature, even at temperatures above the threshold where the particles' entanglement vanishes. This shows for Gibbs spin states that entanglement is not fundamentally necessary for energy teleportation; correlation other than entanglement can suffice. Dissonance-quantum correlation in separable states-is in this regard shown to be a quantum resource for energy teleportation, more dissonance being consistently associated with greater energy yield. We compare energy teleportation from particle A to B in Gibbs states with direct local energy extraction by a general quantum operation on B and find a temperature threshold below which energy extraction by a local operation is impossible. This threshold delineates essentially two regimes: a high temperature regime where entanglement vanishes and the teleportation generated by other quantum correlations yields only vanishingly little energy relative to local extraction and a second low-temperature teleportation regime where energy is available at B only by teleportation.
Energy in a multipartite quantum system appears from an operational perspective to be distributed to some extent non-locally because of correlations extant among the system's components. This non-locality allows users to transfer, in effect, locally accessible energy between sites of different system components by local operations and classical communication (LOCC). Quantum energy teleportation is a three-step LOCC protocol, accomplished without an external energy carrier, for effectively transferring energy between two physically separated, but correlated, sites. We apply this LOCC teleportation protocol to a model Heisenberg spin particle pair initially in a quantum thermal Gibbs state, making temperature an explicit parameter. We find in this setting that energy teleportation is possible at any temperature, even at temperatures above the threshold where the particles' entanglement vanishes. This shows for Gibbs spin states that entanglement is not fundamentally necessary for energy teleportation; correlation other than entanglement can suffice. Dissonance—quantum correlation in separable states—is in this regard shown to be a quantum resource for energy teleportation, more dissonance being consistently associated with greater energy yield. We compare energy teleportation from particle A to B in Gibbs states with direct local energy extraction by a general quantum operation on B and find a temperature threshold below which energy extraction by a local operation is impossible. This threshold delineates essentially two regimes: a high temperature regime where entanglement vanishes and the teleportation generated by other quantum correlations yields only vanishingly little energy relative to local extraction and a second low-temperature teleportation regime where energy is available at B only by teleportation.
How we identify heat and work is a fundamental question in modern quantum thermodynamics. Usually, heat and work are attributed to changes in the density matrix and the Hamiltonian, respectively, during time-evolution processes in quantum systems. Recently, it has been recognized that this identification is ambiguous. Furthermore, quantum thermodynamics involving quantum measurement is still under development. Motivated by these on-going works, we consider a quantum many-body system from which we extract energy by local operations and classical communication (LOCC) according to the quantum energy teleportation (QET) protocol. The central idea to define heat and work unambiguously is based on a sharp insight into the optimization condition of LOCC. When LOCC is optimized, the extractable energy by QET becomes a daemonic ergotropy; thus, it can be attributed as work. On the other hand, when LOCC is not optimized, we have not squeezed out all the energy with the unitary operation. It means there is uncontrollable energy left in the system. The uncontrollable energy can be attributed as heat after careful treatment of many-body interactions. The heat term consists of nonlocal correlation due to communication between remote participants, and the correlation cannot be directly observed for the participant in the subsystem. Thus, this feature is consistent with the traditional perspective of heat as an uncontrollable energy. To deeply understand the nature of heat, we derive two types of generalized Clausius inequality in our effective quantum thermodynamics, and discuss the direction of the inequality. To justify our perspective, we examine a one-dimensional Kitaev-like model and discuss the physical meaning of effective temperature in our thermodynamics.
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.
FINDING: Quantum teleportation transmits state (not matter) over 1,400 km; recent work extends to teleporting *energy* (not just information) via superconducting hardware — a shift from information-theoretic to thermodynamic transport. | MATH: Core protocol uses Bell-state measurement (maximally entangled pair, e.g., |Φ⁺⟩ = (|00⟩+|11⟩)/√2), classical communication of 2 bits, and unitary correction (Pauli X/Z). Energy teleportation (arXiv:2301.02666) uses a two-qubit Hamiltonian H = H_A + H_B + V, with V = g(σ_x^A σ_x^B + σ_y^A σ_y^B)/2; energy extracted from Bob's qubit after Alice's local measurement, with average extracted energy ⟨E⟩ = −(g/2)(1 − ⟨σ_z^A⟩⟨σ_z^B⟩) — negative for entangled states, enabling net energy transfer. | CONNECTION: The Bell basis is a 4-element orthonormal set in ℂ²⊗ℂ², isomorphic to the vertices of a tetrahedron (root system A₃, symmetry group S₄). The energy teleportation coupling g is a spin-spin interaction with SU(2) symmetry; the ratio of extracted energy Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com
Many-body quantum systems in the ground states have zero-point energy due to the uncertainty relation. In many cases, the system in the ground state accompanies spatially entangled energy density fluctuation via the noncommutativity of the energy density operators, though the total energy takes a fixed value, i.e., the lowest eigenvalue of the Hamiltonian. Quantum energy teleportation (QET) is a protocol for the extraction of the zero-point energy out of one subsystem using information of a remote measurement of another subsystem. From an operational viewpoint of protocol users, QET can be regarded as an effective rapid energy transportation without breaking all physical laws, including causality and local energy conservation. In the protocol, the ground-state entanglement plays a crucial role. In this paper, we show analytically for a general class of spin-chain systems that the entanglement entropy is lower bounded by a positive quadratic function of the teleported energy between the regions of a QET protocol. This supports a general conjecture that ground-state entanglement is an evident physical resource for energy transportation in the context of QET. The result may also deepen our understanding of the energy density fluctuation in condensed-matter systems from a perspective of quantum information theory.