Physicists create ‘holographic wormhole’ inside quantum computer

This is among the more fascinating experiments of a generation

TL;DR

A team of physicists has successfully created a wormhole using a quantum computer, marking a groundbreaking achievement in connecting quantum mechanics and general relativity. The wormhole was formed by manipulating qubits in Google’s Sycamore quantum device, teleporting information through it. The experiment supports the holographic principle, suggesting space-time could emerge from quantum systems. This exciting development could pave the way for deeper understanding of quantum gravity, even though its implications for our universe are not yet fully understood.

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Physicists claim to have successfully created the first-ever wormhole, a type of tunnel theorized in 1935 by Albert Einstein and Nathan Rosen, which connects two points by passing through an extra dimension of space.

This wormhole materialized like a hologram from quantum bits of information, or “qubits,” stored in tiny superconducting circuits. By manipulating these qubits, the physicists managed to send information through the wormhole, as reported in Nature.

The research, led by Maria Spiropulu from the California Institute of Technology, employed the “wormhole teleportation protocol” using Google’s quantum computer, Sycamore, located at Google Quantum AI in Santa Barbara, California. This “quantum gravity experiment on a chip,” as Spiropulu described it, marks a significant achievement in the race against other teams, including those using IBM and Quantinuum quantum computers, to achieve wormhole teleportation.

When Spiropulu observed the key sign indicating that qubits had traversed the wormhole, she said, “I was shaken.”

This experiment supports the holographic principle, a sweeping idea about how quantum mechanics and general relativity — the two fundamental theories in physics — interconnect. Physicists have long sought to reconcile these distinct frameworks, one describing atoms and subatomic particles, the other explaining how matter and energy warp space-time, creating gravity. Since the 1990s, the holographic principle has gained traction, suggesting a mathematical equivalence or “duality” between the two theories. It proposes that the bendable space-time described in general relativity is actually a quantum system of particles, with space-time and gravity emerging from quantum effects, much like a 3D hologram is projected from a 2D pattern.

In fact, the new experiment shows that quantum effects, which can be controlled in a quantum computer, can produce phenomena expected in relativity — in this case, a wormhole. The evolving system of qubits on the Sycamore chip “has this really cool alternative description,” said John Preskill, a theoretical physicist at Caltech, who wasn’t involved in the experiment. “You can think of the system in a very different language as being gravitational.”

To clarify, unlike a traditional hologram, the wormhole isn’t visible. According to co-author Daniel Jafferis from Harvard University, the wormhole is a “filament of real space-time,” but it exists in a different reality than the one we and the Sycamore computer occupy. The holographic principle suggests that both the wormhole’s reality and the reality of the qubits are two versions of the same physics, though how to fully understand this duality is still unclear.

There will be varying opinions on what the result means fundamentally. Notably, the holographic wormhole in this experiment involves a different type of space-time than the one we live in. It’s uncertain whether this experiment advances the hypothesis that the space-time in our universe is also holographic, structured by quantum bits.

“I think it is true that gravity in our universe emerges from some quantum [bits], just like this small, one-dimensional wormhole emerges from the Sycamore chip,” Jafferis said. “But we’re not sure yet. We’re still trying to understand it.”

Into the Wormhole

The concept of a holographic wormhole dates back to two unrelated papers published in 1935: one by Einstein and Rosen, known as ER, and another by them and Boris Podolsky, known as EPR. Both papers were initially dismissed as less significant works of Einstein’s career, but that perception has since changed.

In the ER paper, Einstein and Rosen stumbled upon the possibility of wormholes while trying to extend general relativity into a unified theory — a theory not only of space-time but also of the subatomic particles within it. They were investigating space-time anomalies discovered by German physicist Karl Schwarzschild in 1916, shortly after Einstein published his theory of general relativity. Schwarzschild showed that mass can gravitationally collapse into an infinitely small point, creating a singularity where general relativity breaks down. These singularities, now known to exist in black holes, represent places where a quantum theory of gravity is needed.

Einstein and Rosen speculated that Schwarzschild’s math might help incorporate elementary particles into general relativity. To make this work, they removed the singularity from the equations, replacing it with an extra-dimensional tube leading to another part of space-time. Einstein and Rosen believed — incorrectly but with foresight — that these “bridges” or wormholes could represent particles.

Ironically, while trying to link wormholes with particles, they overlooked the peculiar particle phenomenon they had identified two months earlier in the EPR paper: quantum entanglement.

Entanglement occurs when two particles interact, creating a linked state where measuring one particle instantly determines the state of the other, regardless of the distance between them. Einstein called this “spooky action at a distance,” a concept that led him to question quantum theory.

Since the 1990s, entanglement has gained importance due to its role in new types of computations. Entangling two qubits — quantum objects that exist in two states, 0 and 1 — creates four possible states (00, 01, 10, 11) with different probabilities. More qubits exponentially increase the number of possible states, making quantum computers extremely powerful. The most advanced quantum computers today, including Google’s 54-qubit Sycamore, have only been developed in the last few years.

At the same time, quantum gravity researchers are interested in entanglement as the potential “source code” for space-time.

ER = EPR

Talk of emergent space-time and holography began in the late 1980s, when black hole theorist John Wheeler suggested that space-time and all matter within it could arise from information. Dutch physicist Gerard ’t Hooft later wondered if this process might resemble a hologram’s projection. By 1994, Leonard Susskind expanded on ’t Hooft’s idea in a paper titled “The World as a Hologram,” arguing that a region of bendy space-time, as described by general relativity, is equivalent or “dual” to a quantum particle system on its boundary.

In 1997, quantum gravity theorist Juan Maldacena provided a key example of holography, showing that a type of space known as anti-de Sitter (AdS) space is indeed a hologram.

The real universe resembles a de Sitter space, a continuously expanding sphere driven by its own positive energy. In contrast, anti-de Sitter (AdS) space contains negative energy due to a difference in the sign of a constant in the general relativity equations. This gives AdS a “hyperbolic” structure, where objects shrink as they move outward and approach infinitesimal size at the boundary. Maldacena demonstrated that the properties of space-time and gravity in AdS space correspond to a quantum system on its boundary (a conformal field theory, or CFT).

Maldacena’s 1997 paper on “AdS/CFT correspondence” has been referenced over 22,000 times, averaging twice a day. Peter Woit, a physicist from Columbia University, commented that many top theorists have tried for decades to apply ideas based on AdS/CFT. While exploring his AdS/CFT map, Maldacena discovered a link between quantum systems and wormholes. He studied an entanglement pattern between two sets of particles and found that it was mathematically dual to a hologram of two black holes in AdS space, connected by a wormhole.

In 2013, Maldacena realized that this finding might indicate a broader connection between quantum entanglement and wormholes, leading him to develop the cryptic equation “ER = EPR.” This suggests that the Einstein-Rosen bridge (wormholes) between black holes may be formed by EPR-like correlations between their microstates. He theorized that any entangled system might be connected by an ER bridge, hinting that entangled particles in the universe may be connected by wormholes, recording their shared histories.

When Jafferis heard Maldacena discuss ER = EPR, he realized the duality could be used to design custom wormholes by manipulating entanglement patterns. Standard Einstein-Rosen bridges collapse quickly, but Jafferis speculated that physically connecting the two entangled sets of particles could hold the wormhole open, making it traversable. He, Ping Gao, and Aron Wall calculated that by coupling two sets of entangled particles, one could open a wormhole between them and send a qubit through.

Their 2016 discovery introduced a new method for exploring the mechanics of holography. By manipulating entangled particles on one side, they showed it was possible to probe the connection between entangled systems in a way that would hold the wormhole open. Maldacena and others soon proposed that such a traversable wormhole could be realized in a quantum system called the SYK model, which involves particles interacting in groups.

Alexei Kitaev expanded the importance of the SYK model by showing it had a holographic connection to a one-dimensional black hole in AdS space. Maldacena and others suggested using two SYK models linked together to represent the mouths of Jafferis, Gao, and Wall’s wormhole. By 2019, Jafferis and Gao developed a method for teleporting information (a qubit) between two systems using a shock wave of negative energy in the wormhole.

Jafferis’ wormhole became the first concrete realization of ER = EPR, proving the theory for a specific system. Zlokapa, a graduate student, assisted in the experimental verification using quantum computers, which culminated in running a simplified wormhole teleportation protocol on Google’s Sycamore quantum device. The experiment used just seven qubits and a simplified SYK model to show a holographic wormhole.

Zlokapa and Spiropulu’s team simplified the SYK model, reducing the number of interactions while maintaining its holographic properties. They programmed the quantum system and successfully observed a peak in the data, indicating that qubits were teleporting through a wormhole.

This result was compared to the Higgs boson discovery, with an additional finding that “size-winding,” a key signature of holography, also appeared unexpectedly. Jafferis noted that this confirmed the robustness of the holographic duality and provided evidence that the gravitational picture they explored was accurate.

Looking ahead, the experiment opens new possibilities for understanding quantum mechanics and gravity. Susskind and others hope to use wormhole experiments with more qubits to explore the wormhole’s interior and uncover new aspects of quantum gravity. Critics, however, point out that the experiment is based on AdS space, not de Sitter (dS) space like our universe.

Physicists have long sought a holographic duality for de Sitter space, but progress has been slow. Critics argue that the differences between AdS and dS spaces make a smooth transition between them impossible, yet some researchers believe studying simpler models like AdS can still yield valuable insights. Susskind proposes that a variant of the SYK model might represent de Sitter space, opening new avenues for exploration.

Though challenges remain, the discovery of a holographic wormhole marks an important step forward in quantum gravity research.