Firenze: confermata in laboratorio teoria da Nobel

lowenz · 23-12-2008, 00:24

Eheh, ogni tanto una bella notizia.

La posto qui e non in scienza e tecnica giusto per l'alto valore simbolico che ha, oggi che si parla tanto di ricerca (ma è meglio che non dica a che livelli se ne parla

)

La conferma è di una RILEVANTE importanza attualmente teorica ma in futuro (solita storia che gli imprenditori non mandano giù facilmente

) anche pratica, per la computazione quantistica presumibilmente:

http://physicsworld.com/cws/article/news/37106

A property of laser light first predicted in 1963 by the future Nobel laureate Roy Glauber has been verified by physicists in Italy.

Marco Bellini and colleagues from the University of Florence have shown that if one photon is removed from a beam of coherent laser light, the light remains in the same coherent state. According to Bellini, the ability to remove photons from light in this way could be used to develop quantum information and quantum metrology systems.

Despite being comprised of many photons, the output of a laser can often be described as a single quantum (or coherent) state. What Glauber did in 1963 — five years after the first laser was built — was to use quantum electrodynamics to show that the addition and subtraction of single photons from coherent light does not affect its coherence. Changing the number of photons only changes the amplitude of the beam.

Verifying this prediction in the lab has proved far from easy because it is very difficult to remove just one photon at a time from a beam. Another big problem has been actually measuring the coherence of the beam before and after the photon has been removed.

About five years ago, however, Bellini and colleagues started developing a way of removing single photons from a laser beam. In their experiments, which they report in New Journal of Physics, a relatively intense laser beam is first passed through a highly-reflective beam splitter, which deflects most of the light into a coherent reference beam.

The rest of the light travels straight through the beam splitter and emerges as relatively weak but still coherent beam. This beam is then sent through a second beam splitter, which is extremely inefficient and only occasionally diverts a photon away from the beam and into a very sensitive detector (see “One photon out”). When the detector “clicks”, the team can be fairly certain that just one photon has been removed from the beam.

In their most recent study, the team then looked for any changes in the coherence of the beam by recombining it with the reference beam in an interferometer. With each successive “click”, the interferometer is used to measure a different aspect of the phase and amplitude of beam. These data are then analysed using a technique called quantum state tomography, which gives the complete quantum state of the light.

The team found that removing a photon from the light did not change its coherent state — verifying Glauber's 1963 prediction.

In similar experiments Bellini and colleagues have worked out a way to add a single photon to a coherent state and have confirmed another pillar of quantum optics called “noncommutivity” — that removing a photon from a coherent state and then adding a photon is not the same as adding a photon and then removing a photon.

As a result, the team has assembled a “toolbox” for quantum optics that includes the “creation” and “annihilation” operators that add and remove photons, as well as establishing the noncommutivity of these operators. They have also shown that a coherent state is an “eigenstate” of the annihilation operator by showing that the state is not altered by the removal of a photon.

Bellini told physicsworld.com that these tools should allow physicists to engineer quantum-optical states that are optimized for a range of applications such as measuring very small changes in distance or the secure transmission of quantum information.

LUVІ · 23-12-2008, 00:46

Ma come azz si fa a ELIMINARE UN FOTONE da un fascio di luce coerente?!?!?!?! Va beh, in scienza e tecnica, please

LuVi

lowenz · 23-12-2008, 00:52

Quote:

Originariamente inviato da LUVІ

Ma come azz si fa a ELIMINARE UN FOTONE da un fascio di luce coerente?!?!?!?! Va beh, in scienza e tecnica, please

LuVi

C'è scritto eh

Quote:

This beam is then sent through a second beam splitter, which is extremely inefficient and only occasionally diverts a photon away from the beam and into a very sensitive detector (see “One photon out”). When the detector “clicks”, the team can be fairly certain that just one photon has been removed from the beam.

dantes76 · 23-12-2008, 01:38

sempre meglio di un catorcio con le ali, che fa qualcosa che gli altri fanno da 50 anni...

yggdrasil · 23-12-2008, 01:50

questo è il motivo per cui la ricerca è importante...

ConteZero · 23-12-2008, 08:12

Gli daranno una gratifica di 50 euro.

trallallero · 23-12-2008, 08:28

Quote:

Originariamente inviato da ConteZero

Gli daranno una gratifica di 50 euro.

lorde ...

Fradetti · 23-12-2008, 09:14

Quote:

Originariamente inviato da ConteZero

Gli daranno una gratifica di 50 euro.

e hai dimenticato la doverosa stretta di mano

Pucceddu · 23-12-2008, 09:17

Quote:

Originariamente inviato da trallallero

lorde ...

in diverse tranches...

ConteZero · 23-12-2008, 09:25

Quote:

Originariamente inviato da Pucceddu

in diverse tranches...

Accreditate direttamente sulla Social Card.

SaettaC · 23-12-2008, 09:39

Quote:

Originariamente inviato da Pucceddu

in diverse tranches...

rigorosamente postdatate

lowenz · 23-12-2008, 10:26

E la pacca sulla spalla?

Pucceddu · 23-12-2008, 10:34

Quote:

Originariamente inviato da trallallero

lorde ...

Quote:

Originariamente inviato da lowenz

E la pacca sulla spalla?

Sostituita col calcinculo

Fides Brasier · 23-12-2008, 10:54

Quote:

Originariamente inviato da SaettaC

rigorosamente postdatate

che non godra' della detassazione

deggungombo · 23-12-2008, 11:27

Quote:

Originariamente inviato da lowenz

http://physicsworld.com/cws/article/news/37106

Bellini told physicsworld.com that these tools should allow physicists to engineer quantum-optical states that are optimized for a range of applications such as measuring very small changes in distance or the secure transmission of quantum information.[/i]

mi manca tantissimo studiare queste robe

Froze · 23-12-2008, 12:06

Quote:

Originariamente inviato da ConteZero

Gli daranno una gratifica di 50 euro.

Quote:

Originariamente inviato da trallallero

lorde ...

Quote:

Originariamente inviato da Pucceddu

in diverse tranches...

Quote:

Originariamente inviato da ConteZero

Accreditate direttamente sulla Social Card.

Quote:

Originariamente inviato da SaettaC

rigorosamente postdatate

Quote:

Originariamente inviato da Fides Brasier

che non godra' della detassazione

Lucrezio · 23-12-2008, 13:01

Spettacolo

Spettacolosa anche l'ennesima riprova sperimentale delle regole di commutazione canoniche per gli operatori bosonici!

Tagliate tagliate... non vi rendete conto che delle nostre facolta' scientifiche si deve andare orgogliosi?

gabi.2437 · 23-12-2008, 14:18

Uhm, sta roba non mi piace, diabolica...nono l'uomo sta andando oltre, la natura va rispettata

lowenz · 23-12-2008, 14:52

Quote:

Originariamente inviato da gabi.2437

Uhm, sta roba non mi piace, diabolica...nono l'uomo sta andando oltre, la natura va rispettata

Poveri fotoni

Nessuno pensa a quel povero fotone tutto solo soletto e non più insieme agli altri?

Gemma · 23-12-2008, 14:59

Quote:

Originariamente inviato da Lucrezio

Spettacolo

Spettacolosa anche l'ennesima riprova sperimentale delle regole di commutazione canoniche per gli operatori bosonici!

Tagliate tagliate... non vi rendete conto che delle nostre facolta' scientifiche si deve andare orgogliosi?

dato l'elevatissimo tasso di a-scientificità della mia mente non tento nemmeno di capire il contenuto dell'articolo.

Ma "la riprova sperimentale delle regole di commutazione canoniche per gli operatori bosonici" sarà il mio nuovo must in citazioni

23-12-2008, 00:24	#1
lowenz Bannato Iscritto dal: Aug 2001 Città: Berghem Haven Messaggi: 13526	Firenze: confermata in laboratorio teoria da Nobel Eheh, ogni tanto una bella notizia. La posto qui e non in scienza e tecnica giusto per l'alto valore simbolico che ha, oggi che si parla tanto di ricerca (ma è meglio che non dica a che livelli se ne parla ) La conferma è di una RILEVANTE importanza attualmente teorica ma in futuro (solita storia che gli imprenditori non mandano giù facilmente ) anche pratica, per la computazione quantistica presumibilmente: http://physicsworld.com/cws/article/news/37106 A property of laser light first predicted in 1963 by the future Nobel laureate Roy Glauber has been verified by physicists in Italy. Marco Bellini and colleagues from the University of Florence have shown that if one photon is removed from a beam of coherent laser light, the light remains in the same coherent state. According to Bellini, the ability to remove photons from light in this way could be used to develop quantum information and quantum metrology systems. Despite being comprised of many photons, the output of a laser can often be described as a single quantum (or coherent) state. What Glauber did in 1963 — five years after the first laser was built — was to use quantum electrodynamics to show that the addition and subtraction of single photons from coherent light does not affect its coherence. Changing the number of photons only changes the amplitude of the beam. Verifying this prediction in the lab has proved far from easy because it is very difficult to remove just one photon at a time from a beam. Another big problem has been actually measuring the coherence of the beam before and after the photon has been removed. About five years ago, however, Bellini and colleagues started developing a way of removing single photons from a laser beam. In their experiments, which they report in New Journal of Physics, a relatively intense laser beam is first passed through a highly-reflective beam splitter, which deflects most of the light into a coherent reference beam. The rest of the light travels straight through the beam splitter and emerges as relatively weak but still coherent beam. This beam is then sent through a second beam splitter, which is extremely inefficient and only occasionally diverts a photon away from the beam and into a very sensitive detector (see “One photon out”). When the detector “clicks”, the team can be fairly certain that just one photon has been removed from the beam. In their most recent study, the team then looked for any changes in the coherence of the beam by recombining it with the reference beam in an interferometer. With each successive “click”, the interferometer is used to measure a different aspect of the phase and amplitude of beam. These data are then analysed using a technique called quantum state tomography, which gives the complete quantum state of the light. The team found that removing a photon from the light did not change its coherent state — verifying Glauber's 1963 prediction. In similar experiments Bellini and colleagues have worked out a way to add a single photon to a coherent state and have confirmed another pillar of quantum optics called “noncommutivity” — that removing a photon from a coherent state and then adding a photon is not the same as adding a photon and then removing a photon. As a result, the team has assembled a “toolbox” for quantum optics that includes the “creation” and “annihilation” operators that add and remove photons, as well as establishing the noncommutivity of these operators. They have also shown that a coherent state is an “eigenstate” of the annihilation operator by showing that the state is not altered by the removal of a photon. Bellini told physicsworld.com that these tools should allow physicists to engineer quantum-optical states that are optimized for a range of applications such as measuring very small changes in distance or the secure transmission of quantum information.

23-12-2008, 00:46	#2
LUVІ Senior Member Iscritto dal: Jun 2006 Città: Roma-Milano Utente:Deberlusconizzato Iscritto:20/2/2000 Status:SuperUtenteAdm Messaggi totali:107634 Auto:BMW X3 3.0 SD M Messaggi: 1722	Ma come azz si fa a ELIMINARE UN FOTONE da un fascio di luce coerente?!?!?!?! Va beh, in scienza e tecnica, please LuVi __________________ Lego ™ Fans Club :: LinkedIn ::Google Maps\|Business View :: Flickr HWU Flickr :: Google Maps\|Business View tours by 360roma.it :: Archivio post: LuVi :: Lucio Virzì 123 photo - le risposte alle tue domande di fotografia

23-12-2008, 01:38	#4
dantes76 Senior Member Iscritto dal: Dec 2002 Città: AnTuDo ---------- Messaggi Totali: 10196 Messaggi: 1521	sempre meglio di un catorcio con le ali, che fa qualcosa che gli altri fanno da 50 anni... __________________ “ Fiat iustitia, et pereat mundus”-המעז מנצח -

23-12-2008, 08:12	#6
ConteZero Senior Member Iscritto dal: Dec 2006 Città: Trapani (TP) Messaggi: 3098	Gli daranno una gratifica di 50 euro. __________________ A casa ho almeno sette PC, in firma non ci stanno

23-12-2008, 13:01	#17
Lucrezio Senior Member Iscritto dal: Dec 2003 Città: Trento, Pisa... ultimamente il mio studio... Messaggi: 4389	Spettacolo Spettacolosa anche l'ennesima riprova sperimentale delle regole di commutazione canoniche per gli operatori bosonici! Tagliate tagliate... non vi rendete conto che delle nostre facolta' scientifiche si deve andare orgogliosi? __________________ "Expedit esse deos, et, ut expedit, esse putemus" (Ovidio) Il mio "TESSORO": SuperMicro 733TQ, SuperMicro X8DAI I5520, 2x Xeon Quad E5620 Westmere, 12x Kingston 4GB DDR3 1333MHz, 4x WD 1Tb 32MB 7.2krpm

23-12-2008, 01:50	#5
yggdrasil Senior Member Iscritto dal: Aug 2008 Messaggi: 808	questo è il motivo per cui la ricerca è importante...

23-12-2008, 10:26	#12
lowenz Bannato Iscritto dal: Aug 2001 Città: Berghem Haven Messaggi: 13526	E la pacca sulla spalla?

23-12-2008, 14:18	#18
gabi.2437 Senior Member Iscritto dal: Sep 2006 Messaggi: 7030	Uhm, sta roba non mi piace, diabolica...nono l'uomo sta andando oltre, la natura va rispettata __________________

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