Origin of end-of-aging and subaging scaling behavior in glassy dynamics

Publication: Research - peer-reviewJournal article

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Linear response functions of aging systems  are  routinely  interpreted using the  scaling variable $t_{\rm obs}/t_{\rm w}^\mu$, where $t_{\rm w}$ is  the time at which the   field conjugated to the response
is turned on or off, and where $t_{\rm obs}$ is the `observation' time elapsed from the field change.
The response curve obtained for different values of $t_w$ are  usually collapsed using 
values of  $\mu$  slightly below  one, a scaling behavior generally known as \emph{sub-aging}. 
  Recent spin glass Thermoremanent Magnetization experiments have  shown that  the value of $\mu$ is strongly
affected by the form of the  initial cooling protocol  (Rodriguez et al., Phys. Rev. Lett. 91, 037203, 2003), and even
 more importantly,   (Kenning et al., Phys. Rev. Lett. 97,  057201, 2006)   that the     $t_{\rm w}$ dependence of the response curves  vanishes  altogether in  the limit $t_{\rm obs} \gg t_{\rm w}$. The latter result shows that
 $t_{\rm obs}/t_{\rm w}^\mu$ scaling of  linear response data cannot be generally valid, thereby casting  some doubt on the theoretical significance of the exponent $\mu$.
In this work,  a common  mechanism is proposed for  the origin  of both  sub-aging and end of aging behavior in glassy dynamics. The mechanism  combines real  and configuration space properties of the  state produced by the initial thermal quench which initiates the aging process.
Original languageEnglish
JournalPhysical Review E. Statistical, Nonlinear, and Soft Matter Physics
Pages (from-to)011108
Number of pages5
StatePublished - 6 Jan 2010