Uniform hopping approach to the ferromagnetic Kondo model at finite temperature

Koller, Winfried; Prüll, Alexander; Evertz, Hans Gerd; Linden, Wolfgang von der

doi:10.1103/physrevb.67.104432

Cited by 19 publications

(7 citation statements)

References 32 publications

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“…For example, the method has been used in studies of a Potts antiferromagnet, 20 random spin systems, 21 quantum systems, [22][23][24] fluids, 25,26 binary Lennard-Jones glass, 27 liquid crystals, 28 polymers, 25,29 proteins, 30,31 other molecular systems, 32,33 atomic clusters, 34 optimization problems, 35 and combinatorial number theory. 36 Generalizations and further studies of this sampling technique have been carried out by several authors.…”

Section: Introductionmentioning

confidence: 99%

A new approach to Monte Carlo simulations in statistical physics: Wang-Landau sampling

Landau¹,

Tsai²,

Exler³

2004

American Journal of Physics

243

183

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We describe a Monte Carlo algorithm for doing simulations in classical statistical physics in a different way. Instead of sampling the probability distribution at a fixed temperature, a random walk is performed in energy space to extract an estimate for the density of states. The probability can be computed at any temperature by weighting the density of states by the appropriate Boltzmann factor. Thermodynamic properties can be determined from suitable derivatives of the partition function and, unlike ''standard'' methods, the free energy and entropy can also be computed directly. To demonstrate the simplicity and power of the algorithm, we apply it to models exhibiting first-order or second-order phase transitions.

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Section: Introductionmentioning

confidence: 99%

A new approach to Monte Carlo simulations in statistical physics: Wang-Landau sampling

Landau¹,

Tsai²,

Exler³

2004

American Journal of Physics

243

183

View full text Add to dashboard Cite

show abstract

“…Although the uniform hopping approach replaces the fluctuating core spins by an average u, it reproduces not only the expectation value of the energy, but also its width with astonishing accuracy, even for higher temperatures. The results of UHA also remain valid upon the inclusion of n.n Coulomb repulsion [17]. All the while, the numerical effort is reduced from sampling over hundreds of thousands of core-spin configurations to scanning the single parameter u within the unit interval.…”

Section: Finite Temperature Uha and Curie Temperaturementioning

confidence: 82%

“…The fact that the results remain valid with inclusion of the Coulomb repulsion indicates that UHA is a reli-able approximative method that can safely be extended to more complicated situations. UHA results [17].…”

Section: Finite Temperature Uha and Curie Temperaturementioning

confidence: 97%

“…This UHA approach was extended to finite temperatures in [17]. To introduce this method, we proceed as follows: For a given core spin configuration S, characterized by the set of angles {θ i , φ i }, we define the average u-value…”

Section: Uniform Hopping Approachmentioning

confidence: 99%

“…It should be pointed out that the one-particle density of states (DOS) is identical in global and local quantization; for details see [17].…”

Section: Monte Carlo Algorithmmentioning

confidence: 99%

See 2 more Smart Citations

Aspects of the FM Kondo Model: From Unbiased MC Simulations to Back-of-an-Envelope Explanations

Daghofer

Koller

Prüll

et al.

Local-Moment Ferromagnets

Self Cite

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Effective models are derived from the ferromagnetic Kondo lattice model with classical corespins, which greatly reduce the numerical effort. Results for these models are presented. They indicate that double exchange gives the correct order of magnitude and the correct doping dependence of the Curie temperature. Furthermore, we find that the jump in the particle density previously interpreted as phase separation is rather explained by ferromagnetic polarons.

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Onset of metallic ferromagnetism in a doped spin–orbital chain

Daghofer

Oleś

Linden

2005

Physica Status Solidi (b)

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Starting from a spin-orbital model for doped manganites, we investigate a competition between ferromagnetic and antiferromagnetic order in a one-dimensional model at finite temperature. The magnetic and orbital order at half filling support each other and depend on a small antiferromagnetic superexchange between t2g spins and on an alternating Jahn-Teller potential. The crossover to a metallic ferromagnetic phase found at finite doping is partly suppressed by the Jahn-Teller potential which may localize eg electrons.[published in phys. stat. sol. 242, 311 (2005)] Copyright line will be provided by the publisher 1 Introduction The transition from an insulating to metallic behavior in doped manganites, observed as a function of temperature or filling, is one of the outstanding problems in the field of strongly correlated systems. The theoretical challenge is to understand a rich variety of metallic, insulating, magnetically ordered and orbital ordered phases of doped manganites in terms of the dynamics of correlated e g electrons which involves their orbital degrees of freedom [1]. Magnetic interactions: spin superexchange (SE) and double exchange (DE), as well as orbital SE, frustrate each other and their competition leads to several magnetic phases, including phase separation [2].While orbital order supports A-type antiferromagnetic (AF) phase in LaMnO 3 [3], one expects that e g orbitals play an important role in the insulating ferromagnetic (FM) phase at finite doping, below the crossover to a metallic FM phase [1]. Here we investigate a one-dimensional (1D) model derived from the realistic spin-orbital model for manganites [3], showing an interplay between spin and orbital order.

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Uniform hopping approach to the ferromagnetic Kondo model at finite temperature

Cited by 19 publications

References 32 publications

A new approach to Monte Carlo simulations in statistical physics: Wang-Landau sampling

A new approach to Monte Carlo simulations in statistical physics: Wang-Landau sampling

Aspects of the FM Kondo Model: From Unbiased MC Simulations to Back-of-an-Envelope Explanations

Onset of metallic ferromagnetism in a doped spin–orbital chain

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