We study various aspects of wormholes that are made traversable by an interaction beween the two asymptotic boundaries. We concentrate on the case of nearly‐ gravity and discuss a very simple mechanical picture for the gravitational dynamics. We derive a formula for the two sided correlators that includes the effect of gravitational backreaction, which limits the amount of information we can send through the wormhole. We emphasize that the process can be viewed as a teleportation protocol where the teleportee feels nothing special as he/she goes through the wormhole. We discuss some applications to the cloning paradox for old black holes. We point out that the same formula we derived for gravity is also valid for the simple SYK quantum mechanical theory, around the thermofield double state. We present a heuristic picture for this phenomenon in terms of an operator growth model. Finally, we show that a similar effect is present in a completely classical chaotic system with a large number of degrees of freedom.
We study various aspects of wormholes that are made traversable by an interaction beween the two asymptotic boundaries. We concentrate on the case of nearly‐ gravity and discuss a very simple mechanical picture for the gravitational dynamics. We derive a formula for the two sided correlators that includes the effect of gravitational backreaction, which limits the amount of information we can send through the wormhole. We emphasize that the process can be viewed as a teleportation protocol where the teleportee feels nothing special as he/she goes through the wormhole. We discuss some applications to the cloning paradox for old black holes. We point out that the same formula we derived for gravity is also valid for the simple SYK quantum mechanical theory, around the thermofield double state. We present a heuristic picture for this phenomenon in terms of an operator growth model. Finally, we show that a similar effect is present in a completely classical chaotic system with a large number of degrees of freedom.
With the long-term goal of studying models of quantum gravity in the lab, we propose holographic teleportation protocols that can be readily executed in table-top experiments. These protocols exhibit similar behavior to that seen in the recent traversable wormhole constructions of [1,2]: information that is scrambled into one half of an entangled system will, following a weak coupling between the two halves, unscramble into the other half. We introduce the concept of teleportation by size to capture how the physics of operator-size growth naturally leads to information transmission. The transmission of a signal through a semi-classical holographic wormhole corresponds to a rather special property of the operator-size distribution we call size winding. For more general systems (which may not have a clean emergent geometry), we argue that imperfect size winding is a generalization of the traversable wormhole phenomenon. In addition, a form of signalling continues to function at high temperature and at large times for generic chaotic systems, even though it does not correspond to a signal going through a geometrical wormhole, but rather to an interference effect involving macroscopically different emergent geometries. Finally, we outline implementations feasible with current technology in two experimental platforms: Rydberg atom arrays and trapped ions.
Abstract Recent gravity discussions of a traversable wormhole indicate that in holographic systems signals generated by a source could reappear long after they have dissipated, with the need of only performing some simple operations. In this paper we argue the phenomenon, to which we refer as “regenesis”, is universal in general quantum chaotic many-body systems, and elucidate its underlying physics. The essential elements behind the phenomenon are: (i) scrambling which in a chaotic system makes out-of-time-ordered correlation functions (OTOCs) vanish at large times; (ii) the entanglement structure of the state of the system. The latter aspect also implies that the regenesis phenomenon requires fine tuning of the initial state. Compared to other manifestations of quantum chaos such as the initial growth of OTOCs which deals with early times, and a random matrix-type energy spectrum which reflects very large time behavior, regenesis concerns with intermediate times, of order the scrambling time of a system. We also study the phenomenon in detail in general two-dimensional conformal field theories in the large central charge limit, and highlight some interesting features including a resonant enhancement of regenesis signals near the scrambling time and their oscillations in coupling. Finally, we discuss gravity implications of the phenomenon for systems with a gravity dual, arguing that there exist regimes for which traversability of a wormhole is quantum in nature, i.e. cannot be associated with a semi-classical spacetime causal structure.
By leveraging shared entanglement between a pair of qubits, one can teleport a quantum state from one particle to another.Recent advances have uncovered an intrinsically many-body generalization of quantum teleportation, with an elegant and surprising connection to gravity.In particular, the teleportation of quantum information relies on many-body dynamics, which originate from strongly interacting systems that are holographically dual to gravity; from the gravitational perspective, such quantum teleportation can be understood as the transmission of information through a traversable wormhole.Here, we propose and analyze a new mechanism for many-body quantum teleportation-dubbed peaked-size teleportation.Intriguingly, peaked-size teleportation utilizes precisely the same type of quantum circuit as traversable wormhole teleportation yet has a completely distinct microscopic origin: It relies upon the spreading of local operators under generic thermalizing dynamics and not gravitational physics.We demonstrate the ubiquity of peaked-size teleportation, both analytically and numerically, across a diverse landscape of physical systems, including random unitary circuits, the Sachdev-Ye-Kitaev model (at high temperatures), one-dimensional spin chains, and a bulk theory of gravity with stringy corrections.Our results pave the way toward using many-body quantum teleportation as a powerful experimental tool for (i) characterizing the size distributions of operators in strongly correlated systems and (ii) distinguishing between generic and intrinsically gravitational scrambling dynamics.To this end, we provide a detailed experimental blueprint for realizing many-body quantum teleportation in both trapped ions and Rydberg atom arrays; effects of decoherence and experimental imperfections are analyzed.
A bstract The rapid development of quantum science and technology is leading us into an era where quantum many-body systems can be comprehended through quantum simulations. Holographic duality, which states gravity and spacetime can emerge from strongly interacting systems, then offers a natural avenue for the experimental study of gravity physics without delving into experimentally infeasible high energies. A prominent example is the simulation of traversable wormholes through the wormhole teleportation protocol, attracting both theoretical and experimental attention. In this work, we develop the theoretical framework for computing the fidelity of wormhole teleportation in N -qubit systems with all-to-all interactions, quantified by mutual information and entanglement negativity. The main technique is the scramblon effective theory, which captures universal out-of-time-order correlations in generic chaotic systems. We clarify that strong couplings between the two systems are essential for simulating the probe limit of semi-classical traversable wormholes using strongly interacting systems with near-maximal chaos. However, the teleportation signal diminishes rapidly when reducing the system size N , requiring a large number of qubits to observe a sharp signature of emergent geometry by simulating the Sachdev-Ye-Kitaev model. This includes both the causal time-order of signals and the asymmetry of the teleportation signal for coupling with different signs. As a comparison, the teleportation signal increases when reducing N in weakly interacting systems. We also analyze the fidelity of the generalized encoding scheme in fermionic string operators.
An accumulation of theoretical evidence contribute to the picture of gravity as a manifestation of quantum entanglement in a certain many-body quantum system. This is in particular expresses in the ER=EPR conjecture, which relates gravitational Einstein-Rosen (ER) bridge with the Einstein-Podolsky-Rosen (EPR) quantum entangled pairs or, more generally, with the so-called Thermofield Double State. In this letter, the ER=EPR conjecture is employed to introduce unitary quantum teleportation protocol, which \emph{recycles} the entanglement forming traversable generalization of the Einstein-Rosen bridge. In consequence, the wormhole remains unaffected by the quantum teleportation. Furthermore, it is shown that the protocol guarantees the unconditional security of the quantum communication. Performance of the protocol is demonstrated in a simple setting with the use of 5-qubit Santiago IBM quantum computer, giving fidelities above the 2/3 classical limit for a representative set of teleported states. Security of the protocol has been supported by experimental studies performed with the use of the noisy quantum processor. Possible generalization of the protocol, which may have relevance in the context of macroscopic gravitational configurations, is also considered.
This thesis studies non-locality in quantum gravity from two directions. The first concerns detection: in AdS/CFT, the gravitational Hamiltonian is a boundary observable, and its correlator with a bulk operator can be nonzero at spacelike separation. We develop a single-copy boundary protocol that exploits this structure to detect a bulk excitation before any causal signal has reached the boundary. The protocol backreacts by inducing an uncertainty in the relative bulk-boundary time shift, and we show that this backreaction controls the tradeoff between detection speed and precision. The protocol fails when the bulk operator can be dressed to commute with the boundary Hamiltonian, a condition satisfied by black hole microstates. We introduce two novel dressed-operator constructions that interpolate between holographic accessibility and effective bulk locality: an emergent clock built from the energy level spacing, and an entanglement-based dressing to an external observer via a quantum wormhole. The second part concerns transport. We study two coupled critical transverse-field Ising chains and show that this system, which has no known geometric dual, exhibits several signatures of traversable wormhole transport: a thermofield-double-like ground state, coherent left-right transfer with a timescale controlled by the Ising CFT scaling dimension, and entanglement dynamics that track the signal.