Quantcast

Researchers blur line between classical, quantum physics by linking chaos and entanglement

Using a small quantum system consisting of three superconducting qubits, researchers at UC Santa Barbara and Google have uncovered a link between aspects of classical and quantum physics thought to be unrelated: classical chaos and quantum entanglement. Their findings suggest that it would be possible to use controllable quantum systems to investigate certain fundamental aspects of nature.

“It’s kind of surprising because chaos is this totally classical concept — there’s no idea of chaos in a quantum system,” Charles Neill, a researcher in the UCSB Department of Physics and lead author of a paper that appears in Nature Physics. “Similarly, there’s no concept of entanglement within classical systems. And yet it turns out that chaos and entanglement are really very strongly and clearly related.”

Initiated in the 15th century, classical physics generally examines and describes systems larger than atoms and molecules. It consists of hundreds of years’ worth of study including Newton’s laws of motion, electrodynamics, relativity, thermodynamics as well as chaos theory — the field that studies the behavior of highly sensitive and unpredictable systems. One classic example of chaos theory is the weather, in which a relatively small change in one part of the system is enough to foil predictions — and vacation plans — anywhere on the globe.

At smaller size and length scales in nature, however, such as those involving atoms and photons and their behaviors, classical physics falls short. In the early 20th century quantum physics emerged, with its seemingly counterintuitive and sometimes controversial science, including the notions of superposition (the theory that a particle can be located in several places at once) and entanglement (particles that are deeply linked behave as such despite physical distance from one another).

And so began the continuing search for connections between the two fields.

All systems are fundamentally quantum systems, according Neill, but the means of describing in a quantum sense the chaotic behavior of, say, air molecules in an evacuated room, remains limited.

Imagine taking a balloon full of air molecules, somehow tagging them so you could see them and then releasing them into a room with no air molecules, noted co-author and UCSB/Google researcher Pedram Roushan. One possible outcome is that the air molecules remain clumped together in a little cloud following the same trajectory around the room. And yet, he continued, as we can probably intuit, the molecules will more likely take off in a variety of velocities and directions, bouncing off walls and interacting with each other, resting after the room is sufficiently saturated with them.

“The underlying physics is chaos, essentially,” he said. The molecules coming to rest — at least on the macroscopic level — is the result of thermalization, or of reaching equilibrium after they have achieved uniform saturation within the system. But in the infinitesimal world of quantum physics, there is still little to describe that behavior. The mathematics of quantum mechanics, Roushan said, do not allow for the chaos described by Newtonian laws of motion.

To investigate, the researchers devised an experiment using three quantum bits, the basic computational units of the quantum computer. Unlike classical computer bits, which utilize a binary system of two possible states (e.g., zero/one), a qubit can also use a superposition of both states (zero and one) as a single state. Additionally, multiple qubits can entangle, or link so closely that their measurements will automatically correlate. By manipulating these qubits with electronic pulses, Neill caused them to interact, rotate and evolve in the quantum analog of a highly sensitive classical system.

The result is a map of entanglement entropy of a qubit that, over time, comes to strongly resemble that of classical dynamics — the regions of entanglement in the quantum map resemble the regions of chaos on the classical map. The islands of low entanglement in the quantum map are located in the places of low chaos on the classical map.

“There’s a very clear connection between entanglement and chaos in these two pictures,” said Neill. “And, it turns out that thermalization is the thing that connects chaos and entanglement. It turns out that they are actually the driving forces behind thermalization.

“What we realize is that in almost any quantum system, including on quantum computers, if you just let it evolve and you start to study what happens as a function of time, it’s going to thermalize,” added Neill, referring to the quantum-level equilibration. “And this really ties together the intuition between classical thermalization and chaos and how it occurs in quantum systems that entangle.”

The study’s findings have fundamental implications for quantum computing. At the level of three qubits, the computation is relatively simple, said Roushan, but as researchers push to build increasingly sophisticated and powerful quantum computers that incorporate more qubits to study highly complex problems that are beyond the ability of classical computing — such as those in the realms of machine learning, artificial intelligence, fluid dynamics or chemistry — a quantum processor optimized for such calculations will be a very powerful tool.

“It means we can study things that are completely impossible to study right now, once we get to bigger systems,” said Neill.




The material in this press release comes from the originating research organization. Content may be edited for style and length. Want more? Sign up for our daily email.

9 thoughts on “Researchers blur line between classical, quantum physics by linking chaos and entanglement”

  1. We be looking forward to your review on how it performedI don get
    the feeling it all that flexible. Also I not looking to
    ream with this.
    dildos cheap vibrators joybnd12952

  2. Fantastic blog site and superb blog post! It is very clear that the author is
    proficient and has a big experience in creating. Would you give some bits of
    advice with regards to the best way to raise authoring skills?
    I am awful as a freelance writer and it’s specifically challenging because professors in our university on a regular basis give us authoring tasks.
    Thinking of this, I couldn’t imagine how can I manage
    the issue without this website resume writing
    service reviews. In-depth overviews of the
    most popular online writing companies can assist each and every customer to pick the proper organization.

  3. WOW just what I was searching for. Came here by
    searching for l8-Hydroxyquinoline Sulfate
    8-Quinophenol sulfate

  4. plan cul filme plan cul aubergenville plan cul bonneuil sur marne cherche plan cul gay plan cul gay video plan cul idf plan cul freyming merlebach les plans
    culs plan cul montelimar plan cul albi plan cul
    carmaux plan cul gay lille plan cul bailleul plan cul tarnos plan cul tournon sur rhone
    plan cul angers plan cul 95 plan cul tergnier plan cul les mureaux plan cul tournon sur rhone plan cul sotteville les rouen plan cul loiret plan cul 976 plan cul
    hotel plan cul sur nice plan cul bayonne plan cul 20 plan cul gay nancy plan cul limeil brevannes plan cul 22 plan cul
    saint esteve plan cul evry cul plan plan cul courcouronnes plan cul 41 comment faire un plan cul chat plan cul plan cul pertuis plan cul oignies plan cul illkirch graffenstaden plan cul beurette paris plan cul dans le var comment trouver des plan cul plan cul dans la region plan cul gay var
    plan cul parthenay plan cul somain plan cul lattes plan cul sodo plan cul sur lille

  5. Excellent weblog right here! Also your web site quite a bit up very
    fast! What host are you using? Can I get your affiliate link on your host?
    I want my website loaded up as quickly as yours lol

  6. 22-M eradication normal with which you’re going to be safe within the audit when data is not recovered unless of course, perhaps, by
    way of large borrowed organization employing multi-million dollar
    high-tech gear After some effort, you can quickly
    find the latest cell phone plan that fits your financial allowance. http://bing.org/contrar32/

Comments are closed.