In recent decades a surprising language has taken hold in the search for quantum gravity: the entropy of entanglement. Juan Maldacena 1997 Institute for Advanced Study proposed a correspondence that equates a quantum field theory without gravity to a gravitational theory in a higher-dimensional spacetime, and that dictionary makes entanglement more than a diagnostic tool. Researchers found that patterns of entanglement in the non-gravitational theory can be read as geometric features in the dual spacetime, turning abstract quantum correlations into concrete spatial structure.
A dictionary between quantum information and geometry
The most direct bridge was identified by Shinsei Ryu and Tadashi Takayanagi 2006 University of Tokyo who argued that entanglement entropy of a region in the boundary theory maps to the area of a minimal surface in the bulk geometry. That proposal reframes the classical relation between horizon area and entropy as a general geometric manifestation of quantum entanglement. Mark Van Raamsdonk 2010 University of British Columbia pushed this further by showing that dialing the entanglement between subsystems in the boundary theory changes the connectivity of the bulk, so that disconnected quantum states correspond to spacetimes that fragment. The implication is profound: spacetime connectivity may be an emergent property produced by many-body quantum entanglement rather than a fundamental stage on which quantum fields act.
From thermodynamics to field laboratories
This perspective resonates with earlier work that connected gravity to thermodynamic or information-theoretic notions. Ted Jacobson 1995 University of Maryland derived Einstein’s equations from an assumption relating horizon entropy to heat flow and the Clausius relation, suggesting that spacetime dynamics encode an underlying statistical or quantum informational microphysics. Experimental and cultural echoes appear in the laboratories and conferences that convene relativists and quantum information scientists in Princeton, Tokyo and Cambridge, where tensor networks and numerical simulations are used as concrete toy models to see how entanglement patterns resemble spatial slices of curved geometry. Brian Swingle 2012 Massachusetts Institute of Technology proposed that specific tensor network constructions mimic the radial geometry of anti-de Sitter space, giving researchers a hands-on way to visualize how entanglement builds space.
Social and scientific stakes
Why this matters for broader science and society is not merely academic. The entanglement-driven view reframes questions about black hole interiors, information loss and the origin of classical spacetime, with implications for how we interpret data from gravitational-wave observatories and quantum experiments. Leonard Susskind 2014 Stanford University and collaborators have connected these ideas to computational notions such as complexity, opening new lines of inquiry on how information processing in quantum systems might set limits on cosmological observables. Culturally, the convergence of communities—quantum information theorists, string theorists, numerical relativists—creates a hybrid research culture in which tools and metaphors migrate across continents and disciplines.
Uniqueness and the path ahead
What makes the phenomenon unique is its reversibility: entanglement is at once a microscopic quantum resource and a macroscopic geometric sculptor. By treating entanglement entropy as a bridge, the field gains a pragmatic route to reconstructing spacetime from quantum data, and a conceptual shift that may ultimately recast gravity as an emergent, information-theoretic phenomenon rather than a primary force of nature.
