## Scientists discover how to use time crystals to power superconductors

Physicists propose using time crystals to bring about a quantum computing revolution.

- A team of scientists proposes using time crystals to power topological superconductors.
- The approach could lead to error-free quantum computers.
- Time crystals appear to break laws of physics.

The concept of time crystals comes from the realm of counterintuitive mind-melding physics ideas that may actually turn out to have real-world applications. Now comes news that a paper proposes merging time crystals with topological superconductors for applications in error-free quantum computing, extremely precise timekeeping and more.

Time crystals were first proposed as hypothetical structures by the Nobel-Prize winning theoretical physicist **Frank Wilczek** and MIT physicists in 2012. The remarkable feature of time crystals is that they would would move without using energy. As such they would appear to break the fundamental physics law of **time-translation symmetry. **They would move while staying in their ground states, when they are at their lowest energy, appearing to be in a kind of perpetual motion. Wilczek offered mathematical proof that showed how atoms of crystallizing matter could regularly form repeating lattices in time, while not consuming or producing any energy.

Time crystals have since been experimentally created in various labs.

Now researchers at the California Institute of Technology (Caltech) and the Weizmann Institute in Israel found that theoretically you can create a system that combines time crystals with so-called topological superconductors.

The field of topology looks at the properties of objects that are unchangeable (or "invariant') despite deformations like stretching, twisting, or bending. In a topological insulator, the properties linked to the electron wave function would be considered topologically invariant.

As the scientists themselves explain, "Time crystals form when arbitrary physical states of a periodically driven system spontaneously break discrete time-translation symmetry." What the researchers noticed is that when they introduced "one-dimensional time-crystalline topological superconductors" they found a fascinating interaction where "time-translation symmetry breaking and topological physics intertwine—yielding anomalous Floquet Majorana modes that are not possible in free-fermion systems."

Majorana fermions are particles that have their own anti-particles.

### How to tie a quantum knot

*"Physicists Gil Refael and Jason Alicea explain the unique properties of electrons constrained to a 2 Dimensional world, and how they can be used to make noise-proof Quantum Computers."*

The research was led by **Jason Alicea **and **Aaron Chew** from CalTech, as well as **David Mross **from the Weizmann Institute in Israel.

While studying Majorana fermions, the team observed that it is possible to enhance topological superconductors by coupling them to magnetic degrees of freedom that could be controlled. "Then we realized that by turning those magnetic degrees of freedom into a time crystal, topological superconductivity responds in remarkable ways," shared Alicea.

Aaron Chew (left) and David Mross (right).

Credit: Jason Alicea

One way the phenomen noticed by the scientists could be potentially exploited is to create more stable **qubits** - the bit of quantum information in quantum computing. The race to create qubits is at the threshold of bringing on a true quantum technology revolution, as writes Popular Mechanics.

"It's tempting to imagine generating some useful quantum operations by controlling the magnetic degrees of freedom that intertwine with the topological physics. Or perhaps certain noise channels can be suppressed by exploiting time crystals," said Alicea.

Check out their new paper in Physical Review Letters.

## Why the number 137 is one of the greatest mysteries in physics

Famous physicists like Richard Feynman think 137 holds the answers to the Universe.

- The
**fine structure constant**has mystified scientists since the 1800s. - The number
**1/137**might hold the clues to the Grand Unified Theory. - Relativity, electromagnetism and quantum mechanics are unified by the number.

## Americans under 40 want major reforms, expanded Supreme Court

Younger Americans support expanding the Supreme Court and serious political reforms, says new poll.

- Americans under 40 largely favor major political reforms, finds a new survey.
- The poll revealed that most would want to expand the Supreme Court, impose terms limits, and make it easier to vote.
- Millennials are more liberal and reform-centered than Generation Z.

## Can you solve what an MIT professor once called 'the hardest logic puzzle ever'?

Logic puzzles can teach reasoning in a fun way that doesn't feel like work.

- Logician Raymond Smullyan devised tons of logic puzzles, but one was declared by another philosopher to be the hardest of all time.
- The problem, also known as the Three Gods Problem, is solvable, even if it doesn't seem to be.
- It depends on using complex questions to assure that any answer given is useful.

### The Three Gods Problem

<iframe width="730" height="430" src="https://www.youtube.com/embed/UyOGZk7WbIk" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe><p> One of the more popular wordings of the problem is:<br> <br> "Three gods A, B, and C are called, in no particular order, True, False, and Random. True always speaks truly, False always speaks falsely, but whether Random speaks truly or falsely is a completely random matter. Your task is to determine the identities of A, B, and C by asking three yes-no questions; each question must be put to exactly one god. The gods understand English, but will answer all questions in their own language, in which the words for <em>yes</em> and <em>no</em> are <em>da</em> and <em>ja</em>, in some order. You do not know which word means which."<br> <br> Boolos adds that you are allowed to ask a particular god more than one question and that Random switches between answering as if they are a truth-teller or a liar, not merely between answering "da" and "ja." <br> <br> Give yourself a minute to ponder this; we'll look at a few answers below. Ready? Okay. <strong><br> <br> </strong>George Boolos' <a href="https://www.pdcnet.org/8525737F00588A37/file/31B21D0580E8B125852577CA0060ABC9/$FILE/harvardreview_1996_0006_0001_0060_0063.pdf" target="_blank" rel="noopener noreferrer">solution</a> focuses on finding either True or False through complex questions. </p><p> In logic, there is a commonly used function often written as "iff," which means "if, and only if." It would be used to say something like "The sky is blue if and only if Des Moines is in Iowa." It is a powerful tool, as it gives a true statement only when both of its components are true or both are false. If one is true and the other is false, you have a false statement. </p><p> So, if you make a statement such as "the moon is made of Gorgonzola if, and only if, Rome is in Russia," then you have made a true statement, as both parts of it are false. The statement "The moon has no air if, and only if, Rome is in Italy," is also true, as both parts of it are true. However, "The moon is made of Gorgonzola if, and only if, Albany is the capitol of New York," is false, because one of the parts of that statement is true, and the other part is not (The fact that these items don't rely on each other is immaterial for now).</p><p> In this puzzle, iff can be used here to control for the unknown value of "da" and "ja." As the answers we get can be compared with what we know they would be if the parts of our question are all true, all false, or if they differ. </p><p> Boolos would have us begin by asking god A, "Does "da" mean yes if and only if you are True if and only if B is Random?" No matter what A says, the answer you get is extremely useful. As he explains: <br> </p><p> "If A is True or False and you get the answer da, then as we have seen, B is Random, and therefore C is either True or False; but if A is True or False and you get the answer ja, then B is not Random, therefore B is either True or False… if A is Random and you get the answer da, C is not Random (neither is B, but that's irrelevant), and therefore C is either True or False; and if A is Random...and you get the answer ja, B is not random (neither is C, irrelevantly), and therefore B is either True or False."<br> <br> No matter which god A is, an answer of "da" assures that C isn't Random, and a response of "ja" means the same for B. </p><p> From here, it is a simple matter of asking whichever one you know isn't Random questions to determine if they are telling the truth, and then one on who the last god is. Boolos suggests starting with "Does da mean yes if, and only if, Rome is in Italy?" Since one part of this is accurate, we know that True will say "da," and False will say "ja," if faced with this question. </p><p> After that, you can ask the same god something like, "Does da mean yes if, and only if, A is Random?" and know exactly who is who by how they answer and the process of elimination. </p><p> If you're confused about how this works, try going over it again slowly. Remember that the essential parts are knowing what the answer will be if two positives or two negatives always come out as a positive and that two of the gods can be relied on to act consistently. </p><p> Smullyan wrote several books with other logic puzzles in them. If you liked this one and would like to learn more about the philosophical issues they investigate, or perhaps if you'd like to try a few that are a little easier to solve, you should consider reading them. A few of his puzzles can be found with explanations in this <a href="https://www.nytimes.com/interactive/2017/02/11/obituaries/smullyan-logic-puzzles.html" target="_blank" rel="noopener noreferrer">interactive</a>. </p>## New tardigrade species withstands lethal UV radiation thanks to fluorescent 'shield'

Another amazing tardigrade survival skill is discovered.