Tag: quantum

Amplituhedron

Physicists have discovered a jewel-like geometric object that dramatically simplifies calculations of particle interactions and challenges the notion that space and time are fundamental components of reality. “This is completely new and very much simpler than anything that has been done before” Interactions that were previously calculated with mathematical formulas 1000s of terms long can now be described by computing the volume of the corresponding jewel-like “amplituhedron,” which yields an equivalent 1-term expression.

this is remarkable. usually these theories are only accessible to the most mathematically gifted (cf string theory / ed witten)

Majorana fermions

“The search for this particle is for condensed-matter physicists what the Higgs boson search was for high-energy particle physicists. It is a very peculiar object because it is a fermion yet it is its own antiparticle with zero mass and zero charge. Whether or not these particles will work for quantum computing has yet to be seen, but in the process of trying we will learn a lot of unknown quantum physics,. This could open the door to a whole new field of the topological effects of quantum mechanics.”

Time Crystals


Sounds like the plot line from schlocky sf. And then there is this:

It may be possible to exploit time crystals to perform computations using 0 energy. It is interesting to speculate that a quantum mechanical system whose states could be interpreted as a collection of qubits, could be engineered to traverse a programmed landscape of structured states in Hilbert space over time.

2017-01-27: New paper by Norman Yao

If crystals have an atomic structure that repeats in space, like the carbon lattice of a diamond, why can’t crystals also have a structure that repeats in time? That is, a time crystal?

In a paper, he describes exactly how to make and measure the properties of such a crystal, and even predicts what the various phases surrounding the time crystal should be — akin to the liquid and gas phases of ice.

This is not mere speculation. 2 groups have already created the first-ever time crystals, using 2 totally different setups.

2021-08-06: They’re real.

Time crystals illuminate something profound about the nature of time. “However much you try to treat [time] as being just another dimension, it is always kind of an outlier.” Einstein made the best attempt at unification, weaving 3D space together with time into a 4D fabric: space-time. But even in his theory, unidirectional time is unique. With time crystals,, “this is the first case that I know of where all of a sudden time is just 1 of the gang.”

1000x Bandwidth

Stealthy radar systems and the ability to transmit large amounts of data over long distances are a step closer thanks to a technique that could improve the efficiency of modern optics by 1000x. Traditional methods of transmitting data, such as fiber optics or laser-based radar, require 100 photons to transmit 1 bit of data. Now a team can transmit 10 bits on 1 photon – a 1000x improvement. The researchers exploit a phenomenon known as entanglement, in which the quantum state of one photon is linked to that of another, regardless of how far apart they are. Once created, each entangled pair of photons is separated by passing a laser beam made up of them through a filter made from a nonlinear crystal. This splits the beam in 2 so that each exiting beam contains 1 photon of an entangled pair.

Beyond the Heisenberg limit

Assuming that the particles interact with the object, but not with one another, the accuracy of such measurements grows in proportion to the number of particles in the beams, N. By allowing such particle interactions, scientists have now demonstrated a way to break this so-called Heisenberg limit. They used a beam of photons to measure the small magnetic field produced by a gas made up of 1m ultra-cold rubidium atoms. Normally, the spin of each photon would rotate by a certain amount, thanks to its interactions with the magnetic field of the atoms. But the frequency of the photons was chosen so that the photons also interacted with each other when they were in the gas, so that the presence of one photon altered the way a second behaved. These interactions led to a measurement accuracy that grew in proportion to N3/2 – greater than Heisenberg’s limit

i wish i understood this better, but how is that possible?

Entangled DNA

one line of evidence is that a purely classical analysis of the energy required to hold DNA together does not add up. It is possible that DNA is indeed quantum-efficient.

if Grover-algorithmic processing is some sort of fundamental property of nature, then you might expect the genetic material to be synthesized most efficiently when the machinery has a choice of 4 different nucleotides. And when translating these into proteins, a triplet code (which requires 3 processing steps) would function most efficiently when working with a palette of 20 amino acids. I will admit to being unusually susceptible to ideas like this, but that makes the hair stand up on the back of my neck.