Dynamic behavior of the spin-1/2 Ising Model in an oscillating external magnetic field

Yıl 2025, Cilt: 3 Sayı: 1, 34 - 41, 29.05.2025

Ümüt Temizer

https://doi.org/10.70500/bjs.1681654

Öz

The dynamic phase transition (DPT) temperatures and the dynamic phase diagrams are obtained for spin-1/2 Ising system under the presence of a time-dependent oscillating external magnetic field using the method that was purposed by Meijer and Edwards [ANNALS of PHYSICS, 54, 240 (1969)] within the framework of the Bethe or constant coupling theory. The time variation of magnetization is investigated to find the phases in the system. Thermal behavior of the average magnetization is studied to characterize the nature (continuous and discontinuous) of transitions and to obtain the dynamic phase transition temperatures. The DPT temperatures are found always a second-order; hence there can be no tricritical point separating lines of first- and second-order dynamic phase transitions. This result agrees with the dynamic Monte-Carlo (MC) simulations of a two-dimensional kinetic spin-1/2 Ising model in an oscillating external magnetic field.

Anahtar Kelimeler

Bethe Approximation , Dynamic phase transitions , Dynamic Phase Diagrams

Salınımlı bir dış manyetik alan içinde spin-1/2 Ising modelinin dinamik davranışı

Öz

Dinamik faz geçiş (DPT) sıcaklıkları ve dinamik faz diyagramları, Meijer ve Edwards [ANNALS of PHYSICS, 54, 240 (1969)] tarafından Bethe veya sabit çiftlenim teorisi çerçevesinde amaçlanan yöntem kullanılarak, zaman bağımlı salınımlı dış manyetik alanın varlığında spin-1/2 Ising sistemi için elde edilir. Sistemdeki fazları bulmak için mıknatıslanmanın zamana göre değişimi incelenir. Ortalama mıknatıslanmanın termal davranışı, geçişlerin doğasını (sürekli ve süreksiz) karakterize etmek ve dinamik faz geçiş sıcaklıklarını elde etmek için incelenir. DPT sıcaklıkları her zaman ikinci dereceden bulunur; bu nedenle birinci ve ikinci dereceden dinamik faz geçişlerinin çizgilerini ayıran üçlü kritik nokta olamaz. Bu sonuç, salınımlı bir dış manyetik alanda iki boyutlu kinetik spin-1/2 Ising modelinin dinamik MC simülasyonlarıyla uyumludur.

Anahtar Kelimeler

Bethe Yaklaşımı , Dinamik Faz Geçişleri , Dinamik Faz Diyagramları

Kaynakça

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