438 research outputs found
Magnetic Relaxation Phenomena in a CuMn Spin Glass
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
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
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-MartÃnez & 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
'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
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
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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