438 research outputs found

    Magnetic Relaxation Phenomena in a CuMn Spin Glass

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    Experiments on the temperature and time dependence of the response function and the field cooled magnetisation of a Cu(Mn) spin glass at temperatures below the zero field spin glass temperature are used to explore the non-equilibrium nature of the underlying spin configuration. The results imply that a certain spin configuration is imprinted on the system as the temperature is decreased at a constant cooling rate. The cooling rate governs the magnitude of the FC magnetisation (M_{FC}(H,T)). Any intermittent halt at a constant temperature, T_{i}, imprints an extended spin configuration, a process that is reflected e.g. in a downward relaxation of M_{FC}. On continued cooling at the same rate, the magnitude of M_{FC}(T) remains at a lower level than that of a continuous cooling curve. These results are put into the context of the corresponding behaviour of the response function as observed in measurements of the relaxation of the zero field cooled magnetisation.Comment: 6 pages, 7 figure

    Memory interference effects in spin glasses

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    When a spin glass is cooled down, a memory of the cooling process is imprinted in the spin structure. This memory can be disclosed in a continuous heating measurement of the ac-susceptibility. E.g., if a continuous cooling process is intermittently halted during a certain aging time at one or two intermediate temperatures, the trace of the previous stop(s) is recovered when the sample is continuously re-heated [1]. However, heating the sample above the aging temperature, but keeping it below Tg, erases the memory of the thermal history at lower temperatures. We also show that a memory imprinted at a higher temperature can be erased by waiting a long enough time at a lower temperature. Predictions from two complementary spin glass descriptions, a hierarchical phase space model and a real space droplet picture are contested with these memory phenomena and interference effects. [1] K. Jonason, E. Vincent, J. Hammann, J. P. Bouchaud and P. Nordblad, Phys. Rev. Lett. 31, 3243 (1998).Comment: 7 pages, 1 LaTex file + 5 figures in EPS Revised version of June 17, 1999 (minor changes), to appear in EPJ B around November 9

    Thinking Bigger and Better about "Bad Apples": Evolutionary Industrial/Organizational psychology and the Dark Triad

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    The focal article by Guenole (2014) correctly contends that industrial– organizational (I–O) psychology has been overly reliant on the Big Five or the five-factor model (Benet-Martínez & John, 1998). Although popular and useful, the Big Five also tends to be limited in two important ways. The Big Five is a set of atheoretically derived, descriptive adjectives, and it tends to better tap ‘‘positive’’ aspects of people’s personality over ‘‘negative’’ or ‘‘darker’’ sides. A number of authors have highlighted the importance of examining ‘‘darker’’ aspects of people’s personality both outside (Jonason, Li, Webster, & Schmitt, 2009; Lee & Ashton, 2005; Paulhus & Williams, 2002) and within (Hogan & Hogan, 2001; Jonason, Slomski, & Partyka, 2012) the workplace. As potential mechanisms to explore the ‘‘darker’’ aspects of the workplace, the author of the focal article suggests the Dark Triad of personality (i.e., narcissism, psychopathy, and Machiavellianism). Although the focal article was not solely about these three, we use them as examples to illustrate a broader point: An evolutionary perspective can provide a foundational theory through which workplace phenomenon can be examined with greater richness

    Playing Hard-to-get: Manipulating one's Perceived Availability as a Mate

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    'Playing hard-to-get' is a mating tactic in which people give the impression that they are ostensibly uninterested to get others to desire them more. This topic has received little attention because of theoretical and methodological limitations of prior work. We present four studies drawn from four different American universities that examined playing hard-to-get as part of a supply-side economics model of dating. In Studies 1a (N=100) and 1b (N=491), we identified the tactics that characterize playing hard-to-get and how often men and women enact them. In Study 2 (N=290), we assessed reasons why men and women play hard-to-get along with the personality traits associated with these reasons. In Studies 3 (N=270) and 4 (N=425), we manipulated the rate per week prospective mates went out with people they had just met and assessed participants' willingness to engage in casual sex and serious romantic relationships with prospective mates (Study 3) and the money and time they were willing to invest in prospective mates (Study 4). We frame our results using a sexual economics model to understand the role of perceived availability in mating dynamics

    Memory and superposition in a spin glass

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    Non-equilibrium dynamics in a Ag(Mn) spin glass are investigated by measurements of the temperature dependence of the remanent magnetisation. Using specific cooling protocols before recording the thermo- or isothermal remanent magnetisations on re-heating, it is found that the measured curves effectively disclose non-equilibrium spin glass characteristics such as ageing and memory phenomena as well as an extended validity of the superposition principle for the relaxation. The usefulness of this "simple" dc-method is discussed, as well as its applicability to other disordered magnetic systems.Comment: REVTeX style; 8 pages, 4 figure

    Relaxation of the field-cooled magnetization of an Ising spin glass

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    The time and temperature dependence of the field-cooled magnetization of a three dimensional Ising spin glass, Fe_{0.5}Mn_{0.5}TiO_{3}, has been investigated. The temperature and cooling rate dependence is found to exhibit memory phenomena that can be related to the memory behavior of the low frequency ac-susceptibility. The results add some further understanding on how to model the three dimensional Ising spin glass in real space.Comment: 8 pages RevTEX, 5 figure
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