Dynamically Induced Frustration as a Route to a Quantum Spin Ice State in Tb₂Ti₂O₇ via Virtual Crystal Field Excitations and Quantum Many-Body Effects

The Tb₂Ti₂O₇ pyrochlore magnetic material is attracting much attention for its spin liquid state, failing to develop long-range order down to 50 mK despite a Curie-Weiss temperature θ_CW∼-14  K. In this Letter we reinvestigate the theoretical description of this material by considering a quantum model of independent tetrahedra to describe its low-temperature properties. The naturally tuned proximity of this system near a Néel to spin ice phase boundary allows for a resurgence of quantum fluctuation effects that lead to an important renormalization of its effective low-energy spin Hamiltonian. As a result, Tb₂Ti₂O₇ is argued to be a quantum spin ice. We put forward an experimental test of this proposal using neutron scattering on a single crystal.