In 2010, physicist Mark Van Raamsdonk proposed a radical idea: spacetime isn't fundamental. It emerges from quantum entanglement between fields. Remove the entanglement, and spacetime tears apart.
This idea remained purely theoretical for 15 years. No one had tested it on real quantum hardware. We built a framework to do exactly that.
Quantum correlations between particles that persist regardless of distance. Einstein called it "spooky action at a distance."
The fabric of the universe — the stage on which all physics plays out. General relativity describes its curvature.
If entanglement creates spacetime, then quantum computers — which create entanglement on demand — can create tiny spacetimes in the lab.
We use two coupled chains of 4 qubits each — a minimal model of two entangled quantum fields. The coupling strength λ controls how much entanglement exists between them.
The experiment runs on IBM Torino (133-qubit Heron r1) and IBM Fez (156-qubit Heron r2) — real quantum processors accessible through the cloud.
Over five days, we ran eight hardware experiments scaling from 8 to 128 qubits, testing different Hamiltonians, measurement bases, and architectures.
Vary coupling strength from 0 to 2.0. Watch cross-chain correlations grow. Coupling ratio: 27.9× above baseline. Spacetime forms as entanglement increases.
Run a single chain without a partner. Result: 10-20× less geometric signal. Geometry requires TWO coupled fields — it's relational, not intrinsic.
Ising (ZZ) vs Heisenberg (ZZ+XX) coupling. Both produce the same geometry curve: r = 0.89 correlation. Different physics, same spacetime.
Double the system size to 8+8. Geometry persists and strengthens. The framework scales.
Use 128 of 133 qubits on IBM Torino. 16 independent experiments running simultaneously. Geometry emerges across the entire processor.
Measure in Z, X, and Y bases. Each basis reveals a different geometric component. The Hamiltonian symmetry determines which direction is strongest.
Combine three bases into a diagonal metric tensor. Positive definite everywhere. 100% triangle inequality satisfaction. This IS a metric.
Apply Jacobson's derivation: G_eff = 1/(4λC). Direction-dependent gravity. Universal total gravitational coupling: r = 0.9987. Singularity at λ=0.
Drag the slider to change the coupling strength λ. The bars show the cross-chain correlation — the geometric signal — measured on IBM Torino hardware.
By measuring in three bases (Z, X, Y), we extract a diagonal metric tensor — the mathematical object that describes the geometry of spacetime. Each component tells you how "deep" spacetime is in that direction.
The Ising Hamiltonian couples in Z, so the Z-component is 10× larger — spacetime is elongated along the coupling direction like a needle. The XY Hamiltonian couples in X and Y, producing a disk-shaped geometry instead. The Hamiltonian determines the shape. The coupling determines the size.
Applying Jacobson's thermodynamic derivation to each tensor component gives direction-dependent gravitational constants. The result: gravity is strongest where spacetime is thinnest.
Cross-field correlations increase smoothly with λ. Coupling ratio: 27.9× (Ising Z-basis).
62–92% correlation collapse at λ=0, consistent with Van Raamsdonk's prediction.
Single-chain control shows 10-20× less signal. Geometry is relational, not intrinsic.
Ising and Heisenberg produce the same geometry curve (r = 0.89). Different matter, same spacetime.
Framework reproduces at 8, 16, and 128 qubits. Geometry persists at all scales tested.
Multi-basis measurement reveals basis-dependent components. Z-coupling produces Z-dominant geometry.
All diagonal components positive at every λ. The emergent structure satisfies the mathematical definition of a metric.
56 out of 56 triangles satisfy the inequality for both Hamiltonians. Distances are consistent.
Ricci scalar analog shows inflection at λ≈0.31 — accelerating to decelerating geometry, analogous to inflation.
Flatness drops from 0.84 (sphere) to 0.07 (needle). The Hamiltonian sculpts the shape of spacetime.
G_eff varies by 10× across directions. Gravity pulls perpendicular to the strongest geometry.
Total G_trace correlates at r = 0.9987 across Hamiltonians. The equivalence principle from entanglement.
This framework is at the trailhead of quantum gravity. The results are consistent with theoretical predictions, but the journey from 8 qubits to a complete theory of quantum gravity is vast.
Run the same experiments on IonQ trapped ion hardware via Amazon Braket. If geometry reproduces on atoms instead of wires, it's a property of quantum mechanics itself.
Ramp coupling from zero across Trotter steps. Watch spacetime emerge from nothing. Measure the curvature history of a toy universe from birth to maturity.
Create a spatial gradient in coupling — strong center, weak edges. Look for a horizon where geometry changes character.
Oscillate coupling sinusoidally. If the oscillation propagates along the chain with delay, that's a propagating disturbance in emergent geometry.