Quantum spin-liquid emerging in two-dimensional correlated Dirac fermions

Understand

At sufficiently low temperatures, condensed-matter systems tend to develop order.

• An exception are quantum spin-liquids, where fluctuations prevent a transition to an ordered state down to the lowest temperatures.
• While such states are possibly realized in two-dimensional organic compounds, they have remained elusive in experimentally relevant microscopic two-dimensional models.
• Here, we show by means of large-scale quantum Monte Carlo simulations of correlated fermions on the honeycomb lattice, a structure realized in graphene, that a quantum spin-liquid emerges between the state described by massless Dirac fermions and an antiferromagnetically ordered Mott insulator.