Coherent Oscillations in an Exciton-Polariton Josephson Junction

Arxiv.org ^ | K. G. Lagoudakis

[Kevmo]

Coherent Oscillations in an Exciton-Polariton Josephson Junction

K. G. Lagoudakis1, B. Pietka1, M. Wouters2, R. André3, B. Deveaud-Plédran1 1ICMP, Ecole Polytechnique Fédérale de Lausanne(EPFL),1015 Lausanne, Switzerland. 2ITP, Ecole Polytechnique Fédérale de Lausanne(EPFL),1015 Lausanne, Switzerland. 3Institut Néel, CNRS, Grenoble, France.

Abstract:

We report on the observation of spontaneous coherent oscillations in a microcavity polariton bosonic Josephson junction. The condensation of exciton polaritons takes place under incoherent excitation in a disordered environment, where double potential wells tend to appear in the disordered landscape. Coherent oscillations set on at an excitation power well above the condensation threshold. The time resolved population and phase dynamics reveal the analogy with the AC Josephson effect. We have introduced a theoretical two-mode model to describe the observed effects, which allows us to explain how the different realizations of the pulsed experiment have a similar phase relation.

----------------------------------

In this work we have provided experimental evidence of coherent oscillations in a Bosonic Josephson junction formed by two exciton polariton condensates created under nonresonant pulsed excitation in a double well geometry. We have shown the simultaneous existence of population and phase oscillations and have carefully evaluated their amplitudes and average values. The saw-tooth like oscillations persist for the whole life time of the condensates and are the polariton analog of the AC Josephson regime. Our theoretical analysis shows that the Josephson oscillations survive the realization averaging linked with the random initial phase, though with reduced amplitude, thanks to a spontaneous synchronization mechanism that only appears above a critical pump intensity. The present realization of the Josephson effect relies on the accidental presence of coupled wells in our disordered microcavity. Controlled growth of polariton traps with mesa structures [18] and micropilars [19] will allow for a more systematic analysis of the different regimes of Josephson oscillations, where polariton-polariton interactions can play a more pronounced role. Also, combining nonresonant with resonant excitation will provide full control over the initial conditions of the Josephson oscillations.

[Kevmo]

The Cold Fusion/LENR Ping List

http://www.freerepublic.com/tag/coldfusion/index?tab=articles

---

http://lenr-canr.org/

[4Runner]

Another “perpetual motion” machine?

[Lazamataz]

Coherent Oscillations in an Exciton-Polariton Josephson Junction

Well thank God for THAT!

[SatinDoll]

“Coherent Oscillations in an Exciton-Polariton Josephson Junction”

You do know this sure sounds naughty, don’t you?

[Kevmo]

-Interesting discussion regarding this paper over on Vortex-L

http://www.mail-archive.com/vortex-l@eskimo.com/msg78659.html

Re: [Vo]:how gamma radiation is thermalized

Axil Axil Sat, 06 Apr 2013 15:05:48 -0700

The horse will never drink muddy water… You know...The pot calling the
kettle black. How can a true believer i the Hydrino theory of the world
make such a judgment? As for “and muddy thinking will not suffice in
science.” A quote from Peter
Hagelsteinabout
the danger of closed minds in science:
“It's(LENR) not going to happen anytime soon, most likely. For example the
physicist who was one of the organisers of the May 1st Baltimore session in
1989 that debunked cold fusion was a fellow by the name of Steve Koonin.
[He] was recently appointed to be under-secretary in charge of research at
the Department of Energy. As a result, basically part of his success and
part of his reputation was made based on killing cold fusion. He's now in a
position of responsibility for research at the DoE, you can imagine what
kind of difficulties that leads to in terms of trying to move cold fusion
research to the point where you get funding, or you try to remove the taint
from it. The folks that debunked cold fusion in 1989, many of them have
profited by their actions, and we will likely continue to pay for that for
years to come.” You know again...The pot calling the kettle black. "The
explanation offered violates conservation of momentum and is obviously
false." Conservation laws are not always conserved on the subatomic scale.
"The paper cited does not mention gammas, requires cryogenic temperatures
near absolute zero, and in point of fact - the effect would be complexly
destroyed by gamma radiation and has no applicability to gamma
shielding." requires
cryogenic temperatures near absolute zero? The reference does not say
this, I know I read the article. The article says
This makes exciton polaritons very attractive in the sense that they are a
high temperature quantum fluid.



300K is the high temperature sited

see

http://www.lpn.cnrs.fr/en/GOSS/CFMC.php



other references say the temperature can range as high as 2600K


I will connect the dots in painful detail because the process is a complex
one for those who require a cool drink. But you deserve the effort needed
to get you to the sparkling purity of that satisfying drink of water.


On Sat, Apr 6, 2013 at 5:15 PM, Jones Beene wrote:

> The horse will never drink muddy water, and muddy thinking will not
> suffice in science.****
>
> ** **
>
> The explanation offered violates conservation of momentum and is obviously
> false.****
>
> ** **
>
> The paper cited does not mention gammas, requires cryogenic temperatures
> near absolute zero, and in point of fact - the effect would be complexly
> destroyed by gamma radiation and has no applicability to gamma shielding.*
> ***
>
> ** **
>
> End of story.****
>
> ** **
>
> *From:* Axil Axil ****
>
> For all those who are interested in how gamma radiation is thermalized in
> hundreds of millions of microvolt thermal quanta, here is a quantum
> mechanical paper which contains a lot of words describing how the
> conditions for thermalization occurs out of the blue.****
>
> This finding is consistent with the long sought after physical
> manifestation of the model called the 'Spin-Boson Model' required to
> thermalize gammas.****
>
> My good fellows, when the answer is handed to you on a plate, look into it!
> ****
>
> But unfortunately we all know “You can take a horse to water but you can’t
> make him drink.”****
>
> Coherent Oscillations in an Exciton-Polariton Josephson Junction ****
>
> arxiv.org/pdf/1004.2216****
>
>
> Cheers: Axil****
>

[Kevmo]

No. One of the more prevailing theories relies upon purely conventional physics — the Widom-Larson theory, which NASA is so enamored with.

[coloradan]

Conservation laws are not always conserved on the subatomic scale.

Example?

[Kevmo]

Example? The classic example is Tunneling. From the article: Here ,LRε are the energies of the modes in the absence of the tunneling coupling Jand γis the linewidth in the linear regime. The nonresonant excitation enters the polariton dynamics through the stimulated relaxation rate ()2RRn. The exciton reservoir density consists of the active excitons that fulfill energy and momentum conservation for scattering into the lower polariton branch.... At high excitation intensity, the growth rate is much larger than the tunneling between the two wellsand the Josephson currents can be neglected during the exponential growth stage of the condensate formation. This implies that the initial randomness of the relative phase does not affect the density dynamics that is therefore deterministic up to small fluctuations.... Finally, our two-mode model also allows us to understand the role of the polariton-polariton interactions on the Josephson oscillations. In the absence of interactions, the oscillation frequency is set by the detuning and tunneling coupling....

[tumblindice]

Surely you’re describing a cold fusion intimate massager,
weaponized for emotional ladies with a 1.2 gigabyte flux capacitor.

I don’t think we should go there. Dayum. (It still gave me a chubby.)

[coloradan]

What exactly isn’t conserved in tunneling? There’s no shortage of, or extra, energy, charge, momentum, or anything else, after than there was before, the tunneling happened. For example, particles can’t tunnel into places they don’t have enough energy to occupy. So what am I missing?

[Nifster]

and just because you have an oscillator means nothing additional. we will see what and where this may lead but right now I can only say okay so what?

[Kevmo]

One of the ways I envision tunneling is the pole vaulter. At no time is the entire mass above the threshold; at no time is the center of mass above the threshold; and yet, the entire mass itself goes over the threshold. It is a pretty good illustration.

To extend the analogy, focusing on the center of mass and saying that it HAS to go above the threshold due to conservation of mass equations is simply wrongheaded. Focusing on conservation of energy on similarly micro-focused aspects of the overall energy system is also wrongheaded.

[Kevmo]

we will see what and where this may lead but right now I can only say okay so what?
***If it turns out to be correct, it will change the world more than automobiles did.

There was a time when the Wright brothers refused to demonstrate flights to anyone who wouldn’t agree to buy their airplanes. Simple enough request. And yet they were presented with an endless parade of sniffers hoping to ferret out their secret without paying. Were the Wright brothers scoundrels? Hell no. Just like you say, “ we will see what and where this may lead”. But if you could get in on the ground floor with the wright brothers between 1903 (when they first flew) and 1908 (when they sold their first airplanes to the army) you’d have been sitting pretty. But scoffers at the time only iterated what you just said, “so what?”...

[Nifster]

don’t hold your breath

[coloradan]

You haven’t answered my question, which is what isn’t conserved in tunneling? QM prevents us from talking about how transitions happen, only what the initial and final states are. If something isn’t conserved, I don’t know what it is, but the apparent physical impossibility of tunneling, in and of itself, isn’t a violation of conservation.

[Kevmo]

Obfuscation. Classic fallacy.

[Nifster]

I notice that you offer nothing specific that these oscillations will be used for, can be sustained by, or any practical application thereof. Even masers and lasers some of which have spontaneous oscillations set up within the medium are of no real use except as science experiments.

finding interesting things out about our world and ts physics is certainly fun but this particular item is of passing interest only....it will be used to try and gain additional funding for further research nothing else

[Nifster]

just keep pushing your delusions maybe one day they will show up riding on unicorns

[Kevmo]

There’s no question to answer if you’re going to say something like, “the apparent physical impossibility of tunneling, in and of itself, isn’t a violation of conservation.”

Read the article. Understand tunneling. Apply that understanding to the current article. Then start asking me questions. But by then it will be too late, freepers will have moved on.

Perhaps you should sign up on Vortex-L to access minds more versed in physics, as well as those versed in the circular reasoning you’ve presented.