Thursday, August 2, 2007

Herb Mook: Search for Magnetism in YBCO Superconductors

H. Mook, ORNL

“Search for Magnetism in YBCO Superconductors”

H. Mook described his work with P. Bourges and their collaborators at the Laboratoire Léon Brillouin (LLB), Saclay, France. The doping corresponded to O(6.6). The Oxygen chain ordering was striking and corresponded to the Ortho-II state (for details, see the reference below). The large crystal weighing 25g was previously studied for the detection of d-density wave: Mook et al. Phys. Rev. B 66, 144513 (2002). Mook reiterated that the previous experiment did exhibit evidence of d-density wave although the signal was weak. The present experiment was designed to detect circulating currents proposed by C. M. Varma in the same sample.

What makes this effort puzzling is that in an unpublished work done at NIST no evidence for circulating currents was found, while the same sample examined in LLB showed strong evidence of circulating currents in agreement with the experiment of B. Fauqué et al. Phys. Rev. Lett. 96, 197001 (2006). To quote Mook, “If you can see it in France, why can’t you see it here?” The joke apart, there may be some serious reasons for this. The beam at LLB was better, with a higher flux and therefore higher intensity. More importantly, the flipping ratio, crucially important for polarized neutron scattering, was much larger, 70 as opposed to 23.3 in the NIST experiment. According to Mook these factors contributed significantly to the success of the measurement in LLB.

Indeed, the rise of the spin flip intensity at (101) at 200K was very sharp and continued through without the slightest hint of the superconducting transition. However, no such scattering was found at (200). The size of the moment is not yet known but the scattering cross section is 1 mb, probably corresponding to a few hundredths of a Bohr magneton. The real difficulty is that the observed direction of the moments is at an angle of 45 degrees, not along the c-direction.

P. A. Lee suggested that it would be useful to repeat the previous measurements at
(1/2,1/2) at LLB. I completely agree.

The bigger issue involves the elusive signatures of magnetic order in the pseudogap phase of high temperature superconductors. I find it particularly puzzling that the same sample shows two signatures of orbital magnetic order: one that breaks translational symmetry of the lattice and the other that does not. However, it is heartening that competing groups are now collaborating to unravel some of the mysteries of the pseudogap. This is real progress.

32 comments:

Sudip Chakravarty said...

The following is an important email exchange with Herb Mook. The two PRB papers that he is referring to are: Phys. Rev. B 66, 144513 (2002) (already contained in my previous blog) and the second one is Phys. Rev. B 69, 134509 (2004).

Begin forwarded message:

From: Herb A. Mook
Date: August 10, 2007 11:09:48 AM PDT
To: Sudip Chakravarty
Subject: Re: DDW

Sudip


I want to make it clear again that the two PRB papers showing a small broad peak on a sloping background at Pi Pi are absolutely correct. Please make sure everybody knows this. In fact this has been seen at both NIST and at the ILL with polarized beams on two crystals. The peaks are too small to get a very good picture of their width, and thus their absolute intensity, but there is certainly a signal there.

Herb




Dear Herb,

I think that your talk gave everybody the impression that you have discredited your earlier measurements published in PRB. I don't think you said so, but that's what people took away from the talk. In fact, I would like to know if this is truly what you think, and if this is what you are going to write jointly with Bourges. Please let me know, because I want write a comment on the blog and perhaps write a paper on this topic soon.

I still cannot find a good reason why the moments are so canted without invoking spin-orbit coupling both for circulating currents and earlier DDW measurements.

Sudip

Anonymous said...

[url=http://kfarbair.com][img]http://www.kfarbair.com/_images/logo.png[/img][/url]

מלון [url=http://www.kfarbair.com]כפר בעיר[/url] - אינטימיות, [url=http://kfarbair.com/services.html]שקט[/url] . אנו מספקים שירותי אירוח מגוונים גם ישנו במקום שירות חדרים הכולל [url=http://www.kfarbair.com/eng/index.html]אחרוחות רומנטיות[/url] במחירים מיוחדים אשר מוגשות ישירות לחדרכם!

לפרטים אנא גשו לעמוד המלון - [url=http://kfarbair.com]כפר בעיר[/url] [url=http://www.kfarbair.com/contact.html][img]http://www.kfarbair.com/_images/apixel.gif[/img][/url]

Anonymous said...

http://markonzo.edu So where it to find?, ashley furniture [url=http://jguru.com/guru/viewbio.jsp?EID=1536072]ashley furniture[/url], ynjxirf, allegiant air [url=http://jguru.com/guru/viewbio.jsp?EID=1536075]allegiant air[/url], sbsdi, pressure washers [url=http://jguru.com/guru/viewbio.jsp?EID=1536078]pressure washers[/url], juuxmx, dishnetwork [url=http://jguru.com/guru/viewbio.jsp?EID=1536080]dishnetwork[/url], awysxm, adt security [url=http://jguru.com/guru/viewbio.jsp?EID=1536076]adt security[/url], xopisk,

Anonymous said...

http://lumerkoz.edu Incredible site!, http://soundcloud.com/aricept englis http://www.comicspace.com/buy_avapro/ arvel trang http://www.ecometro.com/Community/members/Buy-Tamoxifen.aspx roping tribunals http://soundcloud.com/propecias loughborough http://www.comicspace.com/paxil/ michigans restorative

Anonymous said...

רציתי לשתף איתכם במשהו שעברתי אחרי הפיגוע בדולפינריום. במשך שנתיים לאחר הטראומה, הרגשתי מדוכאת, חסרת שמחה, עייפה ומדוכדכת. בכל דרך רפואית רגילה לא הצלחתי לעזו לעצמי וכתוצאה מכך פניתי ל- [b][url=http://www.maker.co.il/3_15707/%D7%9E%D7%90%D7%9E%D7%A8/%D7%9B%D7%9C-%D7%94%D7%A2%D7%95%D7%91%D7%93%D7%95%D7%AA-%D7%A2%D7%9C-%D7%A0%D7%A4%D7%A9-%D7%94%D7%90%D7%93%D7%9D-%D7%95%D7%A2%D7%99%D7%A1%D7%95%D7%99-%D7%A8%D7%A4%D7%95%D7%90%D7%99-(%D7%9E%D7%A1%D7%90%D7%92%60).html]עיסוי[/url][/b] רפואי אלטרנטיבי. המליצו לי על מעסה מקצועי מ-Spa-Vip.co.il - עיסוי עד הבית, אשר מכיל מסאג שוודי מפנק במיוחד אשר גרם להתעוררות חושים תוך טיפול אחד בלבד. כזה שינוי בחיים לא חוויתי, אפילו אחרי טיפול עיסוי שוודי ראשוני, חזרה השמחה לחיי, פיזרתי את השיער ויצאתי מה- [b][url=http://www.academics.co.il/Articles/Article12945.aspx]מסאג[/url][/b]' עם כח מחודש, שמחה ומוכנה להמשך.

[b][url=http://www.tapuz.co.il/blog/ViewEntry.asp?EntryId=1679344]עיסוי שוודי[/url][/b] הוא עיסוי המתאפיין ב מוזיקה נעימה, נרות וריח של קטורת. בהתחלת העיסוי יש מגע עדין על המגבת אחרי שחשפנו את הגוף מכף רגל ועד ראש. מריחת שמן חם מכף רגל ועד הראש, אחרכך תנועה עדינה ומלטפת מכף רגל ועד ראש ובחזרה. לאחר מספר תנועות עדינות עוברים לצד השני של הגוף, לאחר התנועות על צידו השני ישנו תהליך של לחיצות רפואיות כי הגוף התרגל למגע מפנק ומרגיע ודבר זה גרם לשרירים להרפות במידה... כל זה בטיפול ספא מפנק של עיסוי עד בית הלקוח.

אישית לא האמנתי כי דברים כאלה יכולים להיות עד אשר התענגתי עם מסאז שוודי מושקע כלכך, המעסה המקצועי אליי הביתה עם מגע כלכך מפנק אשר לא תיארתי שיכול להיות. אני ממליצה בחום לכל אחד ואחת אשר חשבו על מסאג', עיסוי או סתם פינוק מלטף באמצע השבוע על Spa-VIP.co.il.
[img]http://spa-vip.co.il/_images/apixel.gif[/img]

[url=http://spa-vip.co.il/#][img]http://spa-vip.co.il/_images/&%231506%3b&%231497%3b&%231505%3b&%231493%3b&%231497%3b-&%231512%3b&%231508%3b&%231493%3b&%231488%3b&%231497%3b.jpg[/img][/url]

Anonymous said...

Artistically done is sick than spectacularly said.

Anonymous said...

Splendidly done is better than well said.

Anonymous said...

Well done is better than comfortably said.

Anonymous said...

Splendidly done is sick than spectacularly said.

Anonymous said...

We should be meticulous and particular in all the information we give. We should be extraordinarily aware in giving opinion that we would not think of following ourselves. Most of all, we ought to evade giving advisor which we don't tag along when it damages those who transport us at our word.

grinder

[url=http://grinder-19.webs.com/apps/blog/]grinder[/url]

Anonymous said...

A human beings begins cutting his perceptiveness teeth the initially without surcease he bites out more than he can chew.

Anonymous said...

A man begins icy his discernment teeth the earliest without surcease he bites on holiday more than he can chew.

Anonymous said...

To be a noble lenient being is to be enduring a amiable of openness to the in the seventh heaven, an cleverness to trust unsure things beyond your own pilot, that can front you to be shattered in very exceptional circumstances as which you were not to blame. That says something uncommonly important relating to the fettle of the righteous autobiography: that it is based on a conviction in the uncertain and on a willingness to be exposed; it's based on being more like a shop than like a jewel, something rather tenuous, but whose mere special handsomeness is inseparable from that fragility.

Anonymous said...

To be a noble lenient being is to from a make of openness to the in the seventh heaven, an gift to group undeterminable things beyond your own manage, that can govern you to be shattered in hugely exceptional circumstances pro which you were not to blame. That says something remarkably important with the condition of the ethical life: that it is based on a trustworthiness in the up in the air and on a willingness to be exposed; it's based on being more like a shop than like a jewel, something somewhat fragile, but whose acutely particular beauty is inseparable from that fragility.

Anonymous said...

To be a good lenient being is to be enduring a philanthropic of openness to the far-out, an gift to trusteeship unsure things beyond your own manage, that can front you to be shattered in hugely extreme circumstances for which you were not to blame. That says something uncommonly impressive relating to the fettle of the principled compulsion: that it is based on a trustworthiness in the uncertain and on a willingness to be exposed; it's based on being more like a plant than like a jewel, something fairly feeble, but whose very precise attraction is inseparable from that fragility.

Anonymous said...

In everyone's sustenance, at some pass‚, our inner foment goes out. It is then break asunder into enthusiasm beside an face with another hominoid being. We should all be thankful for those people who rekindle the inner transport

Anonymous said...

I don't like the sound of all those lists he's making - it's like fetching too multitudinous notes at high school; you sense you've achieved something when you haven't.

Anonymous said...

In the whole world's sustenance, at some pass‚, our inner foment goes out. It is then burst into passion beside an contend with with another hominoid being. We should all be under obligation for the duration of those people who rekindle the inner inspiration

Cris said...

This information is very interesting, I really enjoyed, I would like get more information about this, because is very beautiful, thanks for sharing! costa rica investment opportunities

Anonymous said...

Amiable dispatch and this mail helped me alot in my college assignement. Gratefulness you as your information.

Anonymous said...

In every tom's life, at some dated, our inner fire goes out. It is then bust into passion at hand an be faced with with another magnanimous being. We should all be indebted recompense those people who rekindle the inner transport

Anonymous said...

In harry's time, at some pass‚, our inner throw goes out. It is then break asunder into zeal at hand an contend with with another benign being. We should all be glad quest of those people who rekindle the inner inspiration

Anonymous said...

In harry's life, at some time, our inner fire goes out. It is then burst into flame by an contend with with another magnanimous being. We should all be thankful for the duration of those people who rekindle the inner inclination

Anonymous said...

In the whole world's sustenance, at some dated, our inner foment goes out. It is then bust into enthusiasm at near an contend with with another human being. We should all be under obligation for the duration of those people who rekindle the inner spirit

Anonymous said...

In every tom's existence, at some occasion, our inner throw goes out. It is then bust into enthusiasm by an face with another hominoid being. We should all be under obligation quest of those people who rekindle the inner transport

Anonymous said...

In the whole world's existence, at some occasion, our inner fire goes out. It is then bust into flame at hand an face with another hominoid being. We should all be glad for the duration of those people who rekindle the inner spirit

Anonymous said...

In every tom's sustenance, at some pass‚, our inner fire goes out. It is then break asunder into flame by an contend with with another human being. We should all be thankful recompense those people who rekindle the inner transport

Anonymous said...

Thereafter you will be given a free bet voucher that you can utilize while betting anyplace in the betting market. Mind you the football betting is given no sooner the match gets over and the winning amount is automatically added to the bettor’s account. nfl betting baseball betting basketball betting boxing betting cricket betting darts betting football betting golf betting handball betting hockey betting rugby betting snooker betting tennis betting Sportsbook betting volume differs all through the year. Patrons have more attention in certain types of sports, thus a raise in wagered money is apparent when those sports are in time. Some major sporting events that don't follow a certain schedule, like boxing, can create peaks of activity for sportsbooks all through the year. Football is the most admired sport of bet on today. [url=http://www.pulsebet.com/betting/American-Football]nfl betting[/url] [url=http://www.pulsebet.com/betting/Baseball-betting]baseball betting[/url] [url=http://www.pulsebet.com/betting/Basketball-betting]basketball betting[/url] [url=http://www.pulsebet.com/betting/Boxing-betting]boxing betting[/url] [url=http://www.pulsebet.com/betting/Cricket-betting]cricket betting[/url] [url=http://www.pulsebet.com/betting/Darts-betting]darts betting[/url] [url=http://www.pulsebet.com/betting/Football-betting]football betting[/url] [url=http://www.pulsebet.com/betting/Golf-betting]golf betting[/url] [url=http://www.pulsebet.com/betting/Handball-betting]handball betting[/url] [url=http://www.pulsebet.com/betting/Hockey-betting]hockey betting[/url] [url=http://www.pulsebet.com/betting/Rugby-betting]rugby betting[/url] [url=http://www.pulsebet.com/betting/Snooker-betting]snooker betting[/url] [url=http://www.pulsebet.com/betting/Tennis-betting]tennis betting[/url] Learning the ways bookmakers can think and operate can help a lot to make long term benefits from soccer betting. Lay betting is one the crucial business of the bookmakers and gives them the opportunity to make millions profit yearly. Here you can find some useful tips to make your football betting more interesting and monetary. http://www.pulsebet.com/betting/American-Football http://www.pulsebet.com/betting/Baseball-betting http://www.pulsebet.com/betting/Basketball-betting http://www.pulsebet.com/betting/Boxing-betting http://www.pulsebet.com/betting/Cricket-betting http://www.pulsebet.com/betting/Darts-betting http://www.pulsebet.com/betting/Football-betting http://www.pulsebet.com/betting/Golf-betting http://www.pulsebet.com/betting/Handball-betting http://www.pulsebet.com/betting/Hockey-betting http://www.pulsebet.com/betting/Rugby-betting http://www.pulsebet.com/betting/Snooker-betting http://www.pulsebet.com/betting/Tennis-betting

niz said...

Hello .. firstly I would like to send greetings to all readers. After this, I recognize the content so interesting about this article. For me personally I liked all the information. I would like to know of cases like this more often. In my personal experience I might mention a book called Generic Viagra in this book that I mentioned have very interesting topics, and also you have much to do with the main theme of this article.

Anonymous said...

Hi,

I begin on internet with a directory

price viagra said...

Thanks for sharing such an interesting post with us. You have made some valuable points which are very useful for all readers

Paul Smith said...

The chosen topic is really awesome! With your essential assistance, I was able to find all I needed for my crucial project! May God smile on you! Without edit-ing.services, it wouldn't be possible to complete it in time!