Randomness-Induced Quantum Spin Liquid Behavior in the s=1/2 Random-Bond Heisenberg Antiferromagnet on the Pyrochlore...

Area of Science:

• Condensed matter physics
• Quantum magnetism
• Disordered systems

Background:

• The behavior of quantum spin systems with disorder is complex and crucial for understanding emergent phenomena.
• Heisenberg antiferromagnets on frustrated lattices like the pyrochlore present unique challenges due to competing interactions.

Purpose of the Study:

• To investigate the effects of random bonds on the properties of the s=1/2 Heisenberg antiferromagnet on a pyrochlore lattice.
• To identify the ground state and thermal properties of this disordered quantum spin system.

Main Methods:

• Exact diagonalization
• Haldane-de Raedt method

Main Results:

• The study reveals that bond randomness drives the system into a gapless quantum spin liquid (QSL) state.
• This disordered state is identified as the random-singlet state.
• The findings are consistent with experimental observations of gapless QSL behavior in mixed-anion pyrochlore antiferromagnets.

Conclusions:

• Randomness is a key ingredient in realizing gapless quantum spin liquid states in frustrated magnets.
• The random-singlet state provides a theoretical framework for understanding experimental results on materials like Lu2Mo2O5N2.