Physicists make strides in understanding quantum entanglement

Dec 14, 2012
This is a kagome lattice. Credit: N. Mori

While some theoretical physicists make predictions about astrophysics and the behavior of stars and galaxies, others work in the realm of the very small, which includes quantum physics. Such is the case at UC Santa Barbara, where theoretical physicists at the Kavli Institute for Theoretical Physics (KITP) cover the range of questions in physics.

Recently, theoretical physicists at KITP have made important strides in studying a concept in called quantum entanglement, in which electron spins are entangled with each other. Using computers to calculate the extreme version of quantum entanglement –– how the spin of every electron in certain electronic materials could be entangled with another electron's spin –– the research team found a way to predict this characteristic. Future applications of the research are expected to benefit fields such as information technology.

"Quantum entanglement is a strange and non-intuitive aspect of the quantum theory of matter, which has puzzled and intrigued physicists since the earliest days of the quantum theory," said Leon Balents, senior author of a recent paper on this topic published in the journal . Balents is a professor of physics and a permanent member of KITP.

represents the extent to which measurement of one part of a system affects the state of another; for example, measurement of one electron influences the state of another that may be far away, explained Balents. In recent years, scientists have realized that entanglement of electrons is present in varying degrees in . Taking this notion to the extreme is the "quantum spin liquid," a in which every is entangled with another.

Balents said that quantum spin liquids are being sought in experiments on natural and artificial minerals. A key question posed by physicists is how to calculate theoretically which materials are quantum spin liquids. "In our paper, we provide an answer to this question, showing that a precise quantitative measure of 'long-range' entanglement can be calculated for realistic models of electronic materials," said Balents.

"Our results provide a smoking gun signature of this special type of entanglement that determines whether or not a given material is a quantum spin liquid," explained Balents. The results prove that an emblematic example of this type of problem –– material with electron spins residing on the "kagome lattice" –– is indeed a quantum spin liquid, according to Balents. The kagome lattice is a pattern of electron spins named after a type of Japanese fishing basket that this arrangement of spins resembles.

"We expect the technique we developed to have broad applications in the search for these unique quantum states, which in the future may have remarkable applications in information technologies," said Balents.

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vacuum-mechanics
1.8 / 5 (5) Dec 15, 2012
Quantum entanglement represents the extent to which measurement of one part of a system affects the state of another; for example, measurement of one electron influences the state of another that may be far away, explained Balents….

Actually, it seems that there is no direct experiment proves which dictate the existence of the entanglement. And for the Bell inequality, it is just a theoretical prove by using simple algebra which seems not suitable for quantum mechanics. Understanding the mechanism of quantum mechanics (below) may give a right interpretation of the entanglement.
http://www.vacuum...17〈=en
gmurphy
5 / 5 (1) Dec 15, 2012
@vacuum-mechanics, what about the Aspect experiments?
clay_ferguson
2 / 5 (4) Dec 15, 2012
@vaccum-mechanics, Congratulations. You've invented "The Ether". A very old idea that nobody believes any longer. All you do on your website is surmise that there must "be something" that is vibrating, for light to behave as a wave. But you are completely devoid of any new ideas to support your theory. The way most modern physics account for this "something" is by realizing we live in a probably 10 dimensional universe (if not infinite dimensions). Therefore we cannot directly observe all of reality since we are merely a 4D slice in that 10D universe. Or maybe in your mind you "predicted the higgs field". Again Congrats, on your brilliance.
Spacefck
3 / 5 (2) Dec 15, 2012
I'm not a science student so please bare with me, as this is probably a stupid question:

How far away, is it suggested, the entangled particles can be from each other? Because, if it's a distance greater than what the speed of light could traverse instantaneously, wouldn't that mean whatever connection there may be that entangles these particles have to exist in a separate dimension from any of ours, with a velocity that exceeds the speed of light from the start, in order to maintain the effect of one particle 'instantaneously' being affected by the other? If that were the case, it might actually appear to be one particle existing in two different places.

Like I said, i'm not a student of science, so I'm sure what I just said was gibberish, but I do find this interesting. If anybody is willing to take a minute to set me straight, it would be greatly welcomed.
TheGhostofOtto1923
3.1 / 5 (17) Dec 15, 2012
How far away, is it suggested, the entangled particles can be from each other?
Unlimited distance.
Because, if it's a distance greater than what the speed of light could traverse instantaneously
Light has a finite speed and so it always takes time to travel from one place to the next. Entangled particles transfer change of state with no time at all between transmission and reception.
Pressure2
1.8 / 5 (5) Dec 15, 2012
Quote from article: "Quantum entanglement represents the extent to which measurement of one part of a system affects the state of another; for example, measurement of one electron influences the state of another that may be far away,"

There has never been any proof whatsoever that this statement is a fact. Not even remotely.
Lurker2358
1.8 / 5 (5) Dec 15, 2012
The way most modern physics account for this "something" is by realizing we live in a probably 10 dimensional universe (if not infinite dimensions). Therefore we cannot directly observe all of reality since we are merely a 4D slice in that 10D universe. Or maybe in your mind you "predicted the higgs field". Again Congrats, on your brilliance.


Adding more complexity in an attempt to explain something allegedly fundamental is a self contradiction.

Ironically, "fundamental reality" should actually have fewer dimensions or equal dimensions, not more.

Consider, a computer is a 3-d device (plus time, we think,) but it can accurately simulate any number of dimensions, with proper programming.

So a computer model proves that 3 dimensions plus time is all you need to produce any number of dimensions and the laws which control them and their contents.
ValeriaT
1.7 / 5 (6) Dec 15, 2012
How far away, is it suggested, the entangled particles can be from each other
It's the decoherence length, which depends on the wavelength/energy density of particle and many other conditions. It's definitely not the infinite distance, but we are talking about hundreds of kilometers at the case of photons and hundreds of meters at the case of electrons.
Q-Star
3.3 / 5 (7) Dec 15, 2012
It's the decoherence length, which depends on the wavelength/energy density of particle and many other conditions.


Incoherent brain waves lead to increased density also, but they are best modeled with the water waves of a flat surface. And many other conditions.

It's definitely not the infinite distance, but we are talking about hundreds of kilometers at the case of photons and hundreds of meters at the case of electrons.


But I had thought the four hundred meter long electron were the ones with subliminal volume. Is that wrong?

The shorter photons would be more effective in quantization of the outer surface of the flat water wave. The Zephyr effect is well documented both experimentally and in theory.
ValeriaT
1.7 / 5 (6) Dec 15, 2012
You're just twaddling and doing fun from things, which you apparently don't understand. This is not a productive way of discussion.

In quantum mechanics the objects don't travel through the space in classical sense: they dissolve and emerge somewhere else. This action is equivalent to exchange the energy with longitudinal waves at the water surface. But it doesn't violate the causality of special relativity, because nothing actually moves there: the newly formed photon is not equivalent to this old one. They're forming two different particles in classical sense.
Q-Star
3.5 / 5 (8) Dec 15, 2012
This is not a productive way of discussion.


Something I am sure you are an expert on. I mean that from the bottom of my heart, no sarcasm involved.

In quantum mechanics the objects don't travel through the space in classical sense


A truly mind boggling theory, who would have suspected it?

This action is equivalent to exchange the energy with longitudinal waves at the water surface.


Here we go back to classical stuff. Tell me more about these "longitudinal" waves at the water surface. How does that work?

But it doesn't violate the causality of special relativity, because nothing actually moves there: the newly formed photon is not equivalent to this old one. They're forming two different particles in classical sense.


I'm sure that is correct, Zephyr,you have unified general relativity, quantum physics and classical physics. I'll be sending my recommendation to the committee for your Nobel.
ValeriaT
1.7 / 5 (6) Dec 15, 2012
These two examples represent only two limit cases of the motion of real objects. At the water surface the solitons do move both with transverse wave mechanism, both with longitudinal wave mechanism. The general relativity is the abstract theory, which neglects the longitudinal wave mechanism nearly completely. In relativity the quantum effects are impossible, because it would lead into violation of Lorentz symmetry. The quantum mechanics excludes this pure transverse model of particle motion instead. The location of particle is always blurred with uncertainty principle.

The complete unification of both these theories is impossible, as it would require the infinite number of dimensions. Some reconciliation is possible just after introduction of fifth dimension, though (AdS/CFT correspondence operates in five dimensions). The more dimensions, the better.
Q-Star
2.6 / 5 (5) Dec 15, 2012
The more dimensions, the better.


You are living proof of that theory.

But be that as it may let's get back to the matter(& energy) at hand,,,,,

So what you are proposing is that when you quantitize the H20 molecules at the sub-classical level, they interact strongly with virtual photons but not with the real photons,,,, and creates a longitudinal absorption of the relativistic mass?

Is that what you are trying to say?
Q-Star
3.3 / 5 (7) Dec 15, 2012
http://www.aetherwavetheory.info/images/physics/quantum/entangled_pair.gif two examples represent only two limit cases of the motion of real objects.


Those two examples seem to show me a standing wave and a transverse wave. Is the longitudinal wave a virtual wave? Could you post a link to a longitudinal wave precipitating out of an ionized field of table salt?

It sure would help me to see the first convolution of the aether field at the point where it intersects with the planck length. Viewed longitudinally if possible.
ValeriaT
1.7 / 5 (6) Dec 15, 2012
Is the longitudinal wave a virtual wave?
Nope, if you're observing the water surface with waves of light. Yes, if you're forced to observe the water surface with its own waves only (which is the case of the vacuum, too). Such a longitudinal waves still manifest itself with many observable effects, you just cannot follow their phase and amplitude deterministically like at the case of surface (transverse) waves. The longitudinal waves manifest itself like Brownian noise at the water surface and like the CMBR noise in the vacuum. They're forming scalar/gravitational waves in vacuum the same moment. The behaviour of scalar waves is complementary to light waves in many aspects. For example, they're superluminal, they induce negative pressure of the radiation and they're interacting mechanically with vacuum and they do penetrate the massive bodies with compare to light waves. They're forming neutrino solitons in the same way like the light waves are forming photon solitons.
Q-Star
3.3 / 5 (7) Dec 15, 2012
They're forming scalar/gravitational waves in vacuum the same moment. The behaviour of scalar waves is complementary to light waves in many aspects. For example, they're superluminal, they induce negative pressure of the radiation and they're interacting mechanically with vacuum and they do penetrate the massive bodies with compare to light waves. They're forming neutrino solitons in the same way like the light waves are forming photon solitons.


Oh, I see, my fault and my apologies,,, I was unaware that the water waves transduced the transverse waves at the flat surface of the water at superluminal speeds. No wonder I couldn't understand it at first.

Thanks, I think I'm on the right track now.
ValeriaT
1.7 / 5 (6) Dec 15, 2012
Another example of the scalar and transverse wave duality is their absorption with charged particles. The transverse EM waves can interact with electron only when this electron is in motion. The movable electrons can absorb the energy of EM waves and they're excited with it into higher energetic state. The scalar waves are absorbed with electrons only when these electrons cannot move at all. Such an electrons exist inside of superconductors, where the electrons are highly compressed and closely packed each other. These electrons are transparent for light waves, but they're absorbed strongly with scalar waves. So we can make antennas and mirrors for scalar waves with using of superconductors. In these arrangement the scalar waves manifest like real waves. After all, because all light waves do have a longitudinal component, you can detect the scalar waves as so-called evanescent waves at the moment, when you filter-out the transverse component with absorption or total reflection.
ValeriaT
1.7 / 5 (6) Dec 15, 2012
that the water waves transduced the transverse waves at the flat surface of the water at superluminal speeds
The longitudinal waves at the water surface are essentially the sound waves of the underwater and they don't propagate with superluminal speed. They're just propagate with higher speed than the transverse waves. During strong underwater (nuclear) explosions such a waves manifest itself like expanding area of noise. The similar things would happen in the vacuum. The gravitational waves would arrive from all directions at the same moment and they would manifest itself like less or more sudden increase of the CMBR noise intensity. This is how the real gravitational waves from supernova explosions should manifest.
Q-Star
3.3 / 5 (7) Dec 15, 2012
The transverse EM waves can interact with electron only when this electron is in motion.


But what happens when the electron is not in motion? Do the EM waves just reflect off the flat surface of the water waves?

The movable electrons can absorb the energy of EM waves and they're excited with it into higher energetic state.


See how stupid I was, I had thought all electrons could absorb energy, not just the moving ones. Can the electrons that are sitting still and not moving absorb the same amount of energy as the moving ones?

Thanks, I think I am getting excited right along with your electrons.
Q-Star
3.3 / 5 (7) Dec 15, 2012
They're just propagate with higher speed than the transverse waves.


Faster than the superluminal waves? That would make them super-duper-luminal waves.

The similar things would happen in the vacuum.


I thought that there was no vacuum, isn't it filled up with aether? How much aether does it take before the vacuum is no longer empty?
ValeriaT
1.7 / 5 (6) Dec 15, 2012
But what happens when the electron is not in motion? Do the EM waves just reflect off the flat surface of the water waves
These electrons do behave like floaters at the water surface, the motion of which is constrained with vertical shafts. Such a floaters can reflect only waves coming from underwater, but they don't interact with surface waves. These electrons do undulate in time dimension only at place like stationary particles. Only stationary particle can interact with scalar waves.
Q-Star
3 / 5 (6) Dec 15, 2012
But what happens when the electron is not in motion? Do the EM waves just reflect off the flat surface of the water waves
These electrons do behave like floaters at the water surface, the motion of which is constrained with http://www.aether...vaky.gif at place like stationary particles. Only stationary particle can interact with scalar waves.


Sir, I'm not qualified for this level of physics, I was just barely able to understand the superluminal water waves. You'll have to dummy it down a little for me.
ValeriaT
1.7 / 5 (6) Dec 15, 2012
I had thought all electrons could absorb energy, not just the moving ones
Nope, the Dirac's electrons within superconductors of graphene are transparent to light - they don't contribute to the light absorption. Which enables to measure the fine structure constant with graphene, for example - electron transitions don't interfere the measurement in this case.
They're just propagate with higher speed than the transverse waves. Faster than the superluminal waves?
Nope, transverse waves are Maxwell EM waves. The scalar waves are at least 10.000x faster than the Maxwell waves. But in the same way, like at the water surface, there is a smooth transition between transverse and longitudinal waves and the intermediate waves would propagate slower. The Maxwell waves have 2-spin component, which is just emphasized in scalar waves. So you cannot prepare "pure" scalar waves, the EM component will be always present there.
ValeriaT
1.7 / 5 (6) Dec 15, 2012
I was just barely able to understand the superluminal water waves
Underwater waves aren't superluminal, they just play an analogy of superluminal waves in vacuum, because they're faster than the transverse waves. The transverse waves at the water surface play an analogy of the Maxwell's EM waves. We are just using them for observations, because they mediate most of energy with compare to longitudinal waves in the same way, like the waves at the water surface. The surface ripples from underwater explosions can destroy the boats, the underwater waves are harmless, because they're subtle, but they do propagate much faster and at much longer distance. It explains, why longitudinal waves evaded the attention of people up to Tesla times.

Don't search for any complexity in this analogy - this model is so simple, it could be understood before four hundred years already.
Q-Star
3 / 5 (6) Dec 15, 2012
Don't search for any complexity in this analogy - this model is so simple, it could be understood before four hundred years already.


Well Zeph, I'm not 400 years old, so I'll have to wait on a complete understanding.
TheGhostofOtto1923
3.1 / 5 (17) Dec 15, 2012
Quote from article: "Quantum entanglement represents the extent to which measurement of one part of a system affects the state of another; for example, measurement of one electron influences the state of another that may be far away,"

There has never been any proof whatsoever that this statement is a fact. Not even remotely.
Please quote a valid source that confirms this outlandish statement .
ValeriaT
1.8 / 5 (5) Dec 15, 2012
Well Zeph, I'm not 400 years old, so I'll have to wait on a complete understanding.
You're not required to understand the machine code processing for understanding of high level program and vice-versa: the exact knowledge of byte code will not help you in understanding, how the whole program is running. Which is why after all the compiled programs aren't called an "Open source", although just these programs provide the complete description of processing workflow. What is important here, you can provide new testable predictions with this model: you can predict the future.
ValeriaT
1.8 / 5 (5) Dec 15, 2012
Here you can find an example of quantum entanglement, as modeled with water surface analogy of quantum Zeeman effect. In the absence of the simulated magnetic field, both of these rotational states have the same energy. However, when the bath is rotated the energy of the rotational states split into pair of mutually complementary states, with one increasing and the other decreasing – just like the angular-momentum states of an electron in a magnetic field. The team also saw abrupt transitions between energy levels analogous to quantization of energy in entangled system.
Now you can just think, how the water analogy is related to the dense aether model...;-)
douglaskostyk
not rated yet Dec 27, 2012
If the state of one of the pair is simultaneously altered by measuring the other, non-local particle, what is the reference frame for determining simultaneity? There is no absolute simultaneity.
Thrasymachus
1 / 5 (3) Dec 27, 2012
Will you people stop feeding the trolls. Q-star, I'm looking at you.