Calculation of the magnetic field penetration depth for high-Tc cuprate superconductors based on the Interlayer Pair Tunneling model /

In this work, the magnetic field penetration depth for high-Tc cuprate superconductors is calculated using a recent Interlayer Pair Tunneling (ILPT) model proposed by Chakravarty, Sudb0, Anderson, and Strong [1] to explain high temperature superconductivity. This model involves a "hopping" of Cooper pairs between layers of the unit cell which acts to amplify the pairing mechanism within the planes themselves. Recent work has shown that this model can account reasonably well for the isotope effect and the dependence of Tc on nonmagnetic in-plane impurities [2] , as well as the Knight shift curves [3] and the presence of a magnetic peak in the neutron scattering intensity [4]. In the latter case, Yin et al. emphasize that the pair tunneling must be the dominant pairing mechanism in the high-Tc cuprates in order to capture the features found in experiments. The goal of this work is to determine whether or not the ILPT model can account for the experimental observations of the magnetic field penetration depth in YBa2Cu307_a7. Calculations are performed in the weak and strong coupling limits, and the efi"ects of both small and large strengths of interlayer pair tunneling are investigated. Furthermore, as a follow up to the penetration depth calculations, both the neutron scattering intensity and the Knight shift are calculated within the ILPT formalism. The aim is to determine if the ILPT model can yield results consistent with experiments performed for these properties. The results for all three thermodynamic properties considered are not consistent with the notion that the interlayer pair tunneling must be the dominate pairing mechanism in these high-Tc cuprate superconductors. Instead, it is found that reasonable agreement with experiments is obtained for small strengths of pair tunneling, and that large pair tunneling yields results which do not resemble those of the experiments.

Grant of Permission for lease of military lands from Sir Robert Prescott to Thomas Clark, 1798-1801.

Transcript (original spelling and grammar retained): By His Excellency Robert Prescott Esquire, Captain General and Governor in Chief in and over His Majestys Provinces of Upper and Lower Canada, General and Commander in Chief of all His Majesty’s forces in the Provinces of Upper and Lower Canada, Nova Scotia, New Brunswick and their several Dependencies and in the Island of Newfoundland &ca. &ca. &ca. I do hereby authorise and permit Thomas Clark of Queenstown in the County of Lincoln in the Province of Upper Canada merchant to take possession of all that Lot, piece and parcel of Land (being part of the land reserved by his Majesty for Military purposes) situate, lying and being at Queenstown in the Township of Newark, in the Home District in the said Province of Upper Canada, bounded and abutted as follows, that is to say beginning at the Distance of two Chains and ninety links from the South East End of his Majesty’s Store House, the said distance being measured along the Bank up Stream, thence South thirty nine degrees and an half West one Chain and fifty links thence south fifty degrees and an half East one Chain and thirty links thence North thirty nine degrees and an half East to the Edge of the Bank and from thence along the Bank to the place of beginning, containing thirty one perches and one hundred and twenty five square links and to occupy and hold the said Lot, piece and parcel of Land during pleasure subject nevertheless to the provisoes and Conditions herein after contained, that is to say. First on condition that it shall and may be lawful to and for His Majesty his Heirs and Successors and to and for the Commander in Chief of His Majesty Forces for the time being and to and for the Officer commanding his Majesty’s Forces in Upper Canada for the time being and to and for either of them to determine and make void this present permission to occupy during pleasure the said Lot, Piece or Parcel of Land above described at any time hereafter whenever he or they shall see fit so to do without any compensation or indemnification to the said Thomas Clark or any other Person or Persons whosoever for any Loss Injury or Damage which he the said Thomas Clark or any other Person or Persons whosoever may thereby sustain. Secondly on this further Condition that it shall and may be lawful to and for His Majesty his Heirs and Successors and to and for his and their Officers, Soldiers and Servants at any time hereafter by order of the Commander in Chief of His Majesty’s Forces for the time being or by order of the Officer commanding his Majesty’s forces in Upper Canada for the time being or by order of the Officer of His Majesty’s Corps of Royal Engineers commanding in the said Province of Upper Canada for the time being to enter upon the said Lot Piece and parcel of Land which the said Thomas Clark is hereby permitted to occupy during pleasure or upon any part thereof and to take down and from the said Lot piece and parcel of Land or from any part thereof to remove any dwelling House Store or other Buildings on the said Lot, piece or Parcel of Land or any part thereof erected and to remove any goods or Chattels on the said Lot piece and parcel of Land or on any part thereof or on any such dwelling House Store or other building found or being and that His Majesty his Heirs and Successors or any other Person or Persons whosoever shall not be liable or responsible to the said Thomas Clark or to any other Person or Persons whosoever for any Loss, Injury or Damage which he or they shall or may in such case sustain. Thirdly on this further Condition that the said Thomas Clark shall not erect on the said Lot Piece or Parcel of Land which the said Thomas Clark is hereby permitted to occupy during pleasure or upon any part thereof at any time or times hereafter any dwelling House store or other Building whatsoever of Stone or brick or of any other materials wood only exccepted and that if any dwelling House or Store or other building of Stone or brick or of any other materials except wood shall at any time be erected on the said Lot, piece or parcel of Land or upon any part thereof, then and in such case, this present permission and every Clause and Article thereof shall from thenceforth cease and determine and be absolutely and entirely null and void. And lastly on this further Condition that the said Thomas Clark or any other Person whosoever shall not assign this permission to occupy the said Lot, Piece or Parcel of Land above described to any Person of Persons whosoever, and if any such assignment shall be made by the said Thomas Clark or by any other Person in his right, or on his behalf, that then and in such case such assignment and this permission to occupy during pleasure the said Lot piece and parcel of Land above described, and every Clause and Article thereof shall from thenceforth cease and determine and be absolutely and entirely null and void. Given under my hand at the Castle of St. Lewis in the City of Quebec in the Province of Lower Canada this Ninth day of July in the year of our Lord one thousand seven hundred and ninety eight and in the thirty eighth year of His Majesty’s Reign. [Signed here by Robert Prescott] By Order of the Commander in Chief [Signed here by James Green (Illegible signature)] I the said Thomas Clark above named do hereby accept the above written Permission to occupy during pleasure the said Lot piece and parcel of Land above described upon and subject to the several Provisioes and Conditions above written and each and every of them severally and respectively. In witness whereof I have hereunto set my hand the Sixteenth day of August in the year of our Lord one thousand seven hundred and ninety eight and in the thirty eighth year of His Majesty’s Reign. [Signed here by Thomas Clark] Signed in the presence of [Illegible signature – looks like J. M Donell Lt. Col.] [Illegible – looks like 2d. Battn R. C. Sm?] [Signed here by C. Anderson] Whereas Inconveniences did arise from the peculiar situation of the Ground contiguous to the above described Lot of Land and the occupation thereof, if estimated by the above Limits would prove highly disadvantageous to Mr. Thomas Clark be it known that in consideration thereof we do permit the above Lot to extend one half Chain more in length up stream so as to comprehend the space allowed for the Road between Lots Two + Three, and we do hereby appropriate the said additional space wholly to the use of the said Thomas Clark. In witness whereof we have hereunto subscribed this Thirteenth Day of October in the Year of our Lord one thousand Eight Hundred and one. [Signed here by J. M’Donell Lt. Col] 2d. Battn. R. C. [in?] Com of Fort George + Dependencies Robt. Pilkington Captain Royal Engineers

Menu - Dinner given by the Prime Minister of Canada The Right Honourable Brian Mulroney

A menu from a dinner given by The Right Honourable Brian Mulroney and Mrs. Mila Mulroney during a visit by the Prime Minister of the Italian Republic, Giulio Andreotti. The dinner was held March 8, 1992 at The Westin Harbour Castle in Toronto and features Inniskillin wines.