Lease this WebApp and get rid of the ads.
Gravity Busters, U.S.A.
Tue Mar 24, 2009 04:09 (XFF:

The Smithsonian /
NASA Astrophysics Data System
Time scale for magnetic reversal and the topological nonconnectivity threshold

Celardo, G. L.; Barré, J.; Borgonovi, F.; Ruffo, S.
Physical Review E, vol. 73, Issue 1, id. 011108

Anisotropic classical Heisenberg models with all-to-all spin coupling display a topological nonconnectivity threshold (TNT) for any number N of spins. Below this threshold, the energy surface is disconnected in two components with positive and negative total magnetizations, respectively, so that magnetization cannot reverse its sign and ergodicity is broken, even at finite N . Here, we solve the model in the microcanonical ensemble, using a recently developed method based on large deviation techniques, and show that a phase transition is present at an energy higher than the TNT energy. In the energy range between the TNT energy and the phase transition, magnetization changes sign stochastically and its behavior can be fully characterized by an average magnetization reversal time. The time scale for magnetic reversal can be computed analytically, using statistical mechanics. Numerical simulations confirm this calculation and further show that the magnetic reversal time diverges with a power law at the TNT threshold, with a size-dependent exponent. This exponent can be computed in the thermodynamic limit (N→∞) , by the knowledge of entropy as a function of magnetization, and turns out to be in reasonable agreement with finite N numerical simulations. We finally generalize our results to other models: Heisenberg chains with distance-dependent coupling, small 3D clusters with nearest-neighbor interactions, metastable states. We conjecture that the power-law divergence of the magnetic reversal time scale might be a universal signature of the presence of a TNT.

DOI: 10.1103/PhysRevE.73.011108

Gravity Busters, U.S.A.
Drums, Pennsylvania

  • WARNING: Fire and Flames emit No LightAncient of Days, Tue Mar 24 04:03
    Pope PixieGirl, the Bishop of Party Vibe, & Apostles This Letter serves as Ancient Notice (AN) from the ancient Angel Of Light (AOL) same authoured by the Ancient of Days (AD) Homo erectus himself to ... more
    • Re: WARNING: Fire and Flames emit No LightAnonymous, Wed Mar 25 00:38
      Mr Homo erectus have* heat? Buy ice cubes U know where to put them
      • PixieGirl de Pope!GOD, Thu Mar 26 02:16
        p0lygon-Window - he couldnt help but post it three times, lame garry very lame You're right Dumb ..., I could Post it 30 Times And dumb ... you Would still Not know There is NO tranzmission 11 April. ... more
        • Scrivener Error's Corrected (SEC)The Easter Bunny, Fri Mar 27 04:40
          Osama Bin Laden is A Piker! (AP) OBL is A Piker! (AP) He (OBL) does NOT Believe in The Easter Bunny. A! He is fired. He is A Piker. YHWH Allah The Easter Bunny -- Apostles Print (AP) O! Sweet Sixteen ... more
          • Macypmj, Sat Mar 28 22:59
            Your story is Miracle on 34th St re-written ....
            • the Devil, and SatanO! Lucifer, Mon Mar 30 09:40
              the Devil, and Satan Right on Time! Engineered tolerance (+/- 666 seconds) Measured tolerance (+/- 6 seconds) ) Saturday 11th April 2009 A.D. 11:00 ... more
              • tolerancepmj, Tue Mar 31 00:18
                pretty thin right now, Are you calling ME a Jack Ass?
                • Hide Full Headerसिद्धार&, Wed Apr 1 02:12
                  Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8" X-Originating-IP: User-Agent: Web-Based Email 4.14.22 Return-Path: more
    • Gravity Busters, U.S.A. — Garden Key, R., Tue Mar 24 04:09
      • Happy Easter ! Wester ! 7 DaysYHWH Allah, Sat Apr 4 19:21
        Happy Easter ! Wester ! 7 Days,,,,,, more
        • Ol' Harry Houdini '77Old Harry, Thu Apr 9 23:45
          Happy Bash Thursday! WAMKQ WAMPQ WAMUQ Ol' Harry Houdini '77 Dhondini discovered Garry Denke knew 'Nothing'. O! Say See maybe Law of Fives help WM stock.... more
          • Scrivener's Error Cause (SEC) 7 More DeathsDenoco Inc. of Texas, Fri Apr 10 13:47
            Scrivener's Error Cause (SEC) 7 More Deaths "... U ... Koran scholars Virginia!" "... U ... Koran scholars IslamicCity!"... more
            • KUUP of Blood of ChristConfucius Denke, Sun Apr 19 16:34
              Parable HVD 90 -- Christ's wamKq wamUq wahUq wamPq of Blood Scholars Scrivener's Error Kills 16 More Soldiers In Baghdad - Missing Name YHWH Iraq's military said Scholars Scrivener's Error has struck ... more
Click here to receive daily updates