23,565 research outputs found

    Efficient generation of distant atom entanglement

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    We show how the entanglement of two atoms, trapped in distant separate cavities, can be generated with arbitrarily high probability of success. The scheme proposed employs sudden excitation of the atoms proving that the weakly driven condition is not necessary to obtain the success rate close to unity. The modified scheme works properly even if each cavity contains many atoms interacting with the cavity modes. We also show that our method is robust against the spontaneous atomic decay.Comment: 4 pages, 5 figure

    Semantic web learning technology design: addressing pedagogical challenges and precarious futures

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    Semantic web technologies have the potential to extend and transform teaching and learning, particularly in those educational settings in which learners are encouraged to engage with ‘authentic’ data from multiple sources. In the course of the ‘Ensemble’ project, teachers and learners in different disciplinary contexts in UK Higher Education worked with educational researchers and technologists to explore the potential of such technologies through participatory design and rapid prototyping. These activities exposed some of the barriers to the development and adoption of emergent learning technologies, but also highlighted the wide range of factors, not all of them technological or pedagogical, that might contribute to enthusiasm for and adoption of such technologies. This suggests that the scope and purpose of research and design activities may need to be broadened and the paper concludes with a discussion of how the tradition of operaismo or ‘workers’ enquiry’ may help to frame such activities. This is particularly relevant in a period when the both educational institutions and the working environments for which learners are being prepared are becoming increasingly fractured, and some measure of ‘precarity’ is increasingly the norm

    The High Water Mark of Social History in Civil War Studies

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    Just hours before the Army of Northern Virginia raised the white flag at Appomattox Court House, Confederate Colonel Edward Porter Alexander approached his commanding officer, Robert E. Lee, with what he hoped was a game-saving plan. Rather than suffer the mortification of surrendering, Alexander begged Lee to scatter his men across the countryside like “rabbits & partridges” where they could continue waging war, not as regular Confederate soldiers, but as elusive guerrilla fighters. Lee listened patiently to his subordinate’s reasoning for irregular warfare. Before Alexander finished, he reminded Lee that the men were utterly devoted to their commanding general, and that such loyalty would continue to inspire the sacrifice of more blood, even if it meant taking to the woods and fighting like common outlaws. When Alexander concluded his impassioned plea, Lee asked his subordinate to imagine what would happen if he turned Alexander’s suggestion into official policy. But before Alexander had a chance to respond, Lee reminded him that virtually every Southern community had been overrun by Union armies, that farms were in disarray, and that crops were ruined. Lee feared that his veterans, upon returning home, would have no choice but to plunder and rob for survival. It would take no time for his disciplined army to descend into a demoralized mob that would take the rest of the South into a downward spiral of unending and unrestrained violence. “As for myself,” Lee concluded, “while you young men might afford to go to bushwhacking, the only proper & dignified course for me would be to surrender myself & take the consequences of my actions.” [excerpt

    The Trophies of Victory and the Relics of Defeat: Returning Home in the Spring of 1865

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    The remains of a lone apple tree, cut down and carved into small pieces by Confederate soldiers, lay along a rutted dirt road that led to the village of Appomattox Court House. Earlier on 9 April 1865, Robert E. Lee had waited under the shade of the apple tree, anxious to hear from Ulysses S.Grant about surrendering his army. Messages between the generals eventually led to a brief meeting between Lee and two Union staff offices who then secured the parlor in Wilmer McLean\u27s house, where Grant dictated the surrender terms to Lee. As soon as the agreement was signed and Lee walked out the door, Union officers decluttered the parlor with Yankee efficiency, cutting strips of upholstery from plush sofas, breaking chair legs into small keepsakes, and appropriating candleholders and chairs until the room was left barren. [excerpt

    Entangled-state cycles from conditional quantum evolution

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    A system of cascaded qubits interacting via the oneway exchange of photons is studied. While for general operating conditions the system evolves to a superposition of Bell states (a dark state) in the long-time limit, under a particular resonance condition no steady state is reached within a finite time. We analyze the conditional quantum evolution (quantum trajectories) to characterize the asymptotic behavior under this resonance condition. A distinct bimodality is observed: for perfect qubit coupling, the system either evolves to a maximally entangled Bell state without emitting photons (the dark state), or executes a sustained entangled-state cycle - random switching between a pair of Bell states while emitting a continuous photon stream; for imperfect coupling, two entangled-state cycles coexist, between which a random selection is made from one quantum trajectory to another.Comment: 12 pages, 10 figure

    Is There a Southern Doctor in the House?

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    Doctoring the South does not go down easily, but a patient reader will benefit immeasurably from this brilliantly conceived and thoroughly researched book. Stephen Stowe has penetrated the scientific and cultural world of southern physicians during the mid-nineteenth century, showing how white doctors made meaning of their lives as they struggled to gain mastery of the sickly bodies of others. The confrontation between patient and physician, between sickness and health, reveals what Stowe calls the country orthodoxy style of southern practitioners. Country orthodoxy inextricably tied a doctor’s understanding of what it meant to be a professional to his local community. It was within a specific locale that the day-to-day reality of practicing medicine gave shape and meaning to the art of healing. [excerpt

    Into the Murky World of Class Consciousness

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    In a 1975 article on the place of yeomen farmers in a slave society, Eugene D. Genovese identified a critical question concerning the nature of the Old South. The issue, he wrote, is to explain “the degree of class collaboration and social unity” that existed among all whites, which to Genovese appeared “all the more impressive in the face of so many internal strains.” Although some critics mistakenly charged that Genovese argued for non-slaveholder passivity in the face of planter hegemony, he was, in actuality, acknowledging that class relations were permeated with tension and discord, causing bitter resentments that occasionally flared into conflict among white folks. Yet Genovese never found evidence of a populist insurgency against slaveholder authority, a struggle in which the very basis of power was contested. He suggested— what scholars such as Steven Hahn, Lacy Ford, and Stephanie McCurry have more recently developed with amazing sophistication—that an intricate web of political, economic, and cultural relations bound whites together through shared material and ideological interests imbedded in human bondage. [excerpt

    Relevance, Resonance, and Historiography: Interpreting the Lives and Experiences of Civil War Soldiers

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    Carmichael shares his experiences of portraying Corporal Bobby Fields at Appomattox Court House National Historical Park in the summer of 1985. He uses Fields as a conduit to explore the scholarship pertaining to the common soldier of the Civil War and how material culture can provide a new window into understanding of making the battlefield come alive for visitors

    Truth is mighty & will eventually prevail Political Correctness, Neo-Confederates, and Robert E. Lee

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    Jefferson Davis sent Robert E. Lee an unusual note after the battle of Gettysburg. The dispatch did not contain any presidential recommendations or requests, only a clipped article from the Charleston Mercury criticizing Lee and his subordinates for failure in Pennsylvania. Why Davis sent this article is impossible to say, and Lee apparently was not interested in the president’s motivations. The General dismissed newspaper criticism of himself as “harmless,” but the Mercury’s condemnation of the army disturbed him. He considered the charges harmful to the cause, for his officers and soldiers were beyond reproach. Defeat, Lee insisted, was his responsibility alone. “No blame can be attached to the army for its failure to accomplish what was projected by me,” he wrote, “nor should it be censured for the unreasonable expectations of the public. I am alone to blame, in perhaps expecting too much of its prowess & valour. [excerpt
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