Physicists Create Mind-Bending New Phase of Matter That Acts Like It Has Two Time Dimensions

Physicists have created a remarkable, never-before-seen phase of matter in a quantum computer.

Physicists demonstrated a way of storing quantum information that is less prone to errors by subjecting a quantum computer’s qubits to quasi-rhythmic laser pulses based on the Fibonacci sequence.

Physicists have created a remarkable, never-before-seen phase of matter by shining a laser pulse sequence inspired by the Fibonacci sequence at atoms inside a quantum computer. Despite there still being only one singular flow of time, the phase has the benefits of two time dimensions, the physicists reported on July 20 in the journal Nature.

This mind-bending property offers a highly desirable benefit: Information stored in the phase is far more protected against errors than with alternative setups currently used in quantum computers. As a result, the information can exist for far longer without getting garbled, an important milestone for making quantum computing viable, according to study lead author Philipp Dumitrescu.

The approach’s innovative use of an “extra” time dimension “is a completely different way of thinking about phases of matter,” says Dumitrescu, who worked on the project as a research fellow at the Flatiron Institute’s Center for Computational Quantum Physics in New York City. “I’ve been working on these theory ideas for over five years, and seeing them come actually to be realized in experiments is exciting.”

In this quantum computer, physicists created a never-before-seen phase of matter that acts as if time has two dimensions. The phase could help protect quantum information from destruction for far longer than current methods. Credit: Quantinuum

Together with Andrew Potter of the University of British Columbia in Vancouver, Romain Vasseur of the University of Massachusetts, Amherst, and Ajesh Kumar of the University of Texas in Austin, Dumitrescu spearheaded the theoretical component of the research. A team headed by Brian Neyenhuis conducted the experiments on a quantum computer at Quantinuum in Broomfield, Colorado.

Ten atomic ions of the element ytterbium serve as the workhorses of the team’s quantum computer. Each ion is individually held and controlled by electric fields produced by an ion trap and can be manipulated or measured using laser pulses.

Each of those atomic ions function as what physicists dub a quantum bit, or ‘qubit.’ As opposed to conventional computers that quantify information in bits (each representing a 0 or a 1), the qubits used by quantum computers leverage the strangeness of quantum mechanics to store even more information. Just as Schrödinger’s cat is both dead and alive in its box, a qubit can be a 0, a 1, or a mashup — or ‘superposition’ — of both at the same time. That additional information density and the way qubits interact with one another promise to allow quantum computers to solve computational problems far beyond the reach of traditional computers.

The Penrose tiling pattern is a type of quasicrystal, which means that it has an ordered yet never-repeating structure. The pattern, composed of two shapes, is a 2D projection of a 5D square lattice.

However, there’s a big problem: Just as peeking in Schrödinger’s box seals the cat’s fate, so does interacting with a qubit. And that interaction doesn’t even have to be deliberate. “Even if you keep all the atoms under tight control, they can lose their quantumness by talking to their environment, heating up or interacting with things in ways you didn’t plan,” Dumitrescu says. “In practice, experimental devices have many sources of error that can degrade coherence after just a few laser pulses.”

Therefore, the challenge is to make qubits more robust. To do that, physicists can use ‘symmetries,’ which are essentially properties that hold up to change. (For example, a snowflake has rotational symmetry because it looks the same when rotated by 60 degrees.) One method is adding time symmetry by blasting the atoms with rhythmic laser pulses. This approach helps, but Dumitrescu and his collaborators wondered if they could go further. So instead of just one time symmetry, they aimed to add two by using ordered but non-repeating laser pulses.

The best way to understand their approach is by considering something else ordered yet non-repeating: ‘quasicrystals.’ A typical crystal has a regular, repeating structure, like the hexagons in a honeycomb. A quasicrystal still has order, but its patterns never repeat. (Penrose tiling is one example of this.) Even more mind-boggling is that quasicrystals are crystals from higher dimensions projected, or squished down, into lower dimensions. Those higher dimensions can even be beyond physical space’s three dimensions: A 2D Penrose tiling, for instance, is a projected slice of a 5D lattice.

For the qubits, Dumitrescu, Vasseur, and Potter proposed in 2018 the creation of a quasicrystal in time rather than space. Whereas a periodic laser pulse would alternate (A, B, A, B, A, B, etc.), the researchers created a quasi-periodic laser-pulse regimen based on the Fibonacci sequence. In such a sequence, each part of the sequence is the sum of the two previous parts (A, AB, ABA, ABAAB, ABAABABA, etc.). This arrangement, just like a quasicrystal, is ordered without repeating. And, akin to a quasicrystal, it’s a 2D pattern squashed into a single dimension. That dimensional flattening theoretically results in two time symmetries instead of just one: The system essentially gets a bonus symmetry from a nonexistent extra time dimension.

Actual quantum computers are incredibly complex experimental systems, though, so whether the benefits promised by the theory would endure in real-world qubits remained unproven.

Using Quantinuum’s quantum computer, the experientialists put the theory to the test. They pulsed laser light at the computer’s qubits both periodically and using the sequence based on the Fibonacci numbers. The focus was on the qubits at either end of the 10-atom lineup; that’s where the researchers expected to see the new phase of matter experiencing two time symmetries at once. In the periodic test, the edge qubits stayed quantum for around 1.5 seconds — already an impressive length given that the qubits were interacting strongly with one another. With the quasi-periodic pattern, the qubits stayed quantum for the entire length of the experiment, about 5.5 seconds. That’s because the extra time symmetry provided more protection, Dumitrescu says.

“With this quasi-periodic sequence, there’s a complicated evolution that cancels out all the errors that live on the edge,” he says. “Because of that, the edge stays quantum-mechanically coherent much, much longer than you’d expect.”

Though the findings demonstrate that the new phase of matter can act as long-term quantum information storage, the researchers still need to functionally integrate the phase with the computational side of quantum computing. “We have this direct, tantalizing application, but we need to find a way to hook it into the calculations,” Dumitrescu says. “That’s an open problem we’re working on.”

Reference: “Dynamical topological phase realized in a trapped-ion quantum simulator” by Philipp T. Dumitrescu, Justin G. Bohnet, John P. Gaebler, Aaron Hankin, David Hayes, Ajesh Kumar, Brian Neyenhuis, Romain Vasseur and Andrew C. Potter, 20 July 2022, Nature.
DOI: 10.1038/s41586-022-04853-4

Materials SciencePopularQuantum ComputingQuantum MechanicsSimons Foundation
Comments ( 8 )
Add Comment
  • BOB

    I discovered that primes have a pattern but the pattern is never repeated. If you add the digits of potentially prime numbers with column zero ending in (1, 3, 7, 9) to one digit (19 = 10 = 1) they totaled (1, 2, 4, 5, 7, 8) but not in order. Unfortunately not all numbers totalling (1, 2, 4, 5, 7, 8) are primes so I labelled them as quasi primes. Also the digits (1, 2, 4, 5, 7, 8) are not in order nor do primes ever total (3, 6, 9).

    • CJ Dennis

      Every single number whose digits total to 3, 6, or 9 is a multiple of 3. And every single number whose digits total to 9 is a multiple of 9. See if you can work out why! So no prime other than 3 has digits totalling to 3, 6, or 9.

  • Rick

    3,6,9

  • Coktor Dox

    “3, 6, 9, the goose drank wine
    The monkey chew[ed] tobacco on the streetcar line
    The line broke,
    The monkey got choked, [and]
    They all went to heaven in a little rowboat.”
    The answers have been hidden in plain sight for centuries! The Morgenheutegesternwelt was here, now, soon!

  • Nikola Milovic

    HOW LONG WILL SCIENCE WANDER THROUGH THE DARK SPACES OF NOT UNDERSTANDING THE LAWS OF NATURE??
    Everything that happens in the universe, which is related to matter and energy, can only be solved by knowing the two laws of motion. Those laws refer to the movements of celestial bodies and particles, about which science has no knowledge to date!!
    YOU ARE TRYING TO BUILD A QUANTUM COMPUTER IN USE IF YOU DON’T KNOW THE LAW OF PARTICLE MOTION.
    All that these experts present and publish are auto delusions and personal mirages with which they try to solve what they know nothing about!!
    WHAT NEW MATTER AND DOUBLE TIME ?? It is true that their MINDS have been deformed by such experiments which are absolutely contrary to the laws of motion !!
    WHEN SCIENCE CAME TO AWARENESS, IT COULD SOLVE ALL ITS ENIGMAS, IF YOU ACCEPT TO AGREE THAT I EXPLAIN THOSE LAWS OF MOVEMENT WITH WHICH SCIENCE CAN BE DIRECTED TO THE RIGHT PATH OF SOLVING EVERYTHING THAT WAS UNSOLVABLE UNTIL TODAY.
    IF YOU ARE CALM AND READY FOR A DEAL, I AM AT YOUR DISPOSAL!
    HERE I AM!!!!!!!!!!

    • Coktor Dox

      YES I AM CALM!!! YES AS A MAN OF SCIENCE LET’S POLITELY SCREECH AT EACH OTHER ABOUT LAW

  • Ron gerry

    What I don’t get is how most of these self depreciating I knower’s are just reciting what some brilliant mind a few hundred years ago theorized, and claim it proven fact. I don’t know anything about the universe but I try to understand what I can and what our predecessors have imagined and calculated. And also the whole expansion enigma, I think that any gravitational pull greater than our planet would experience time slower, and our perception would be distorted, as 1000’s of years here would be 10’s of years say, close to a black hole especially a super massive one so as we looked further into the cosmos differ areas of the universe would have less expansion compared to our local galaxy

  • Jules Rosen

    Just like looking into the box kills the cat I would imagine that actually getting the readout of the answer from the quasi computer creates a disturbance resulting in a non-answer