Quantum Gravity in the Lab: Teleportation by Size and Traversable Wormholes (1911.06314v2)

Abstract: 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.

Summary of "Quantum Gravity in the Lab: Teleportation by Size and Traversable Wormholes"

The paper "Quantum Gravity in the Lab: Teleportation by Size and Traversable Wormholes" presents protocols for teleportation based on holographic principles, suggesting realizable experiments that could probe models of quantum gravity. The authors propose mechanisms that resemble behaviors seen in theoretical traversable wormhole constructs, where information can travel from one section of an entangled system to another.

Key Concepts and Results

The primary focus of the paper is on two teleportation mechanisms driven by the concept of operator-size growth, a phenomenon related to the scrambling of quantum information in chaotic systems. The paper introduces "teleportation by size," where the transmission of information is related to the size distribution of operators, and "size winding," a property that connects operator-size growth to information transmission through semi-classical holographic wormholes.

1. Size-Dependent Phase Teleportation:
   • At infinite temperature, without reliance on specific energy scales, the protocol involves exploiting fluctuations that connect operator-size distribution to the fidelity of information transfer.
   • The transfer fidelity depends on the size distribution, leading to the possibility of high-fidelity teleportation under specific circumstances, typically characterized by late-time behavior in chaotic systems.
2. Size Winding:
   • For systems with a well-defined holographic dual, size winding corresponds to a precise size-dependent phase that allows for robust information transmission at times near the scrambling time.
   • In this scenario, the size-dependent phase resembles momentum wavefunctions of particles traversing a wormhole, offering a geometric interpretation.

The authors extend these concepts beyond infinite temperature and chaotic regimes, speculating on broader applicability. They prove that the two-sided coupling naturally creates negative energy shockwaves, conceptually allowing information to traverse a wormhole.

Implications and Speculations

Theoretically, this research bridges theoretical constructs like the AdS/CFT correspondence with experimental settings. Practically, it opens avenues to explore quantum gravity aspects using table-top quantum experiments. These insights not only provide tools to paper holographic principles in laboratories but also speculate on the extraction of rich dynamics from chaotic quantum systems. While large-scale quantum simulations remain infeasible in many settings, these protocols potentially offer a manageable path to practical demonstrations of quantum gravity principles.

Furthermore, the paper highlights necessary experimental conditions, such as preparing entangled thermofield double states and implementing precise unitary evolution, for such phenomena to be observed. The realization of these protocols in platforms like Rydberg atoms and trapped ions marks a promising direction toward experimental validation.

Future Directions

The paper identifies several potential research areas, such as:

• Experimentally distinguishing between teleportation "through" the wormhole and other forms of information transfer arising from quantum mechanical interference.
• Exploring "wormhole tomography" for state transfer as a method to probe the internal geometry of quantum simulated wormholes.

Overall, the paper suggests operational pathways to probe and understand the physics of quantum entanglement through emergent space-time concepts and encourages the development of experimental platforms where these phenomena can be realized. The implications for quantum computing, particularly in simulating non-gravitational chaotic systems with gravitational analogies, are profound, pointing toward new insights into holographic dualities and perhaps the geometry of quantum states themselves.