SCES Group logo

Zero-point entropy in the frustrated magnet

Condensed matter physicists have long been puzzled by the "missing entropy" in frustrated magnets. Our work proposes that a finite zero-point entropy, arising from macroscopic ground state degeneracy, is the key to understanding these exotic magnetic states.

Research Highlights:

  • Spin Jam State: Identified a magnetic glassy state in BSZGCO and SCGO known as a "spin jam," characterized by macroscopic ground state degeneracy.
  • Perimeter Scaling: First compelling experimental evidence of zero-point entropy scaling with the boundary length (perimeter) of magnetic domains rather than volume.
  • State Transitions: Elucidated how zero-point entropy varies with spin density, combining spin-jam perimeter scaling with spin-glass characteristics.
Entropy shortfall diagram

Figure: Experimental evidence of entropy shortfall in BSZCGO.

Our findings on perimeter-scaling zero-point entropy in triangular networks of bipyramids have significant implications for understanding glassy states in dense magnetic systems.

Zero-point entropy vs spin density

Full Publication:

C. Piyakulworawat et al., "Zero-point entropies of spin-jam and spin-glass states in a frustrated magnet," Physical Review B 109, 104420 (2024).

View Journal Link Read on arXiv