Quantifying Memory in Spin Glasses

Area of Science:

• Condensed Matter Physics
• Statistical Mechanics
• Complex Systems

Background:

• Spin glasses exhibit unique properties like rejuvenation and memory.
• These phenomena were recently linked to the growth of multiple length scales.
• Previous insights were primarily qualitative, lacking quantitative analysis.

Purpose of the Study:

• To quantitatively analyze the phenomena of spin glass rejuvenation and memory.
• To introduce new coefficients for quantifying memory in spin glasses.
• To demonstrate the physical equivalence of different memory quantification coefficients.

Main Methods:

• Performed numerical simulations using the Janus II supercomputer.
• Conducted comparable experimental studies.
• Analyzed the temperature and waiting-time dependence of memory coefficients.

Main Results:

• Introduced two novel coefficients to quantify spin glass memory.
• Demonstrated that these coefficients are physically equivalent to a previously presented one.
• Showed the temperature and waiting-time dependence of these coefficients.

Conclusions:

• The growth of multiple length scales is the underlying mechanism for spin glass memory and rejuvenation.
• The developed coefficients provide a quantitative framework for studying spin glass dynamics.
• Established the physical equivalence of different approaches to quantifying spin glass memory.