Quantum Glass of Interacting Bosons with Off-Diagonal Disorder.

Area of Science:

• Quantum physics
• Condensed matter physics
• Statistical mechanics

Background:

• The Bose-Hubbard model describes interacting bosons in optical lattices.
• Disorder in quantum systems can lead to novel emergent phenomena.
• Understanding glassy states is crucial for quantum many-body physics.

Purpose of the Study:

• Investigate the ground state properties of disordered interacting bosons.
• Characterize the emergence of a spin-glass-like phase.
• Explore the phase diagram of the Bose-Hubbard model with random tunneling.

Main Methods:

• Utilized the Bose-Hubbard model with Gaussian-distributed random tunneling amplitudes.
• Employed the "n-replica trick" from spin-glass theory to access criticality.
• Applied the Trotter-Suzuki method for statistical density operator decomposition.
• Performed numerical calculations to analyze system behavior.

Main Results:

• Off-diagonal disorder induces a spin-glass-like ground state in bosons.
• Observed randomly frozen quantum-mechanical U(1) phases of bosons.
• Phase diagrams reveal a glassy state influenced by disorder, quantum, and thermal fluctuations.

Conclusions:

• The study demonstrates a novel glassy state in disordered quantum bosons.
• The findings are relevant for quantum simulators, particularly in optical lattices.
• Experimental realization of this disordered boson system is proposed.