Is the Orbital-Selective Mott Phase Stable against Interorbital Hopping?

Area of Science:

• Condensed Matter Physics
• Strong Correlation Physics

Background:

• The localization-delocalization transition is central to strong correlation physics.
• Multiorbital systems exhibit orbital-selective Mott phases (OSMPs), where the transition is orbital-dependent.
• The impact of interorbital hopping on OSMPs is not well understood.

Purpose of the Study:

• Investigate the effect of nonlocal interorbital hopping on orbital-selective Mott phases.
• Determine the stability of OSMPs in the presence of interorbital hopping.
• Clarify the nature of the phase transition at low temperatures.

Main Methods:

• Employed single-site dynamical mean-field theory (DMFT) to model interorbital hopping.
• Utilized numerical renormalization group (NRG) as a DMFT impurity solver.
• Performed analytical arguments and numerical simulations.

Main Results:

• Nonlocal interorbital hopping induces local hybridization.
• The OSMP is unstable at zero temperature due to interorbital hopping to metallic orbitals.
• The coherence scale is exponentially suppressed, leading to a crossover, not a quantum critical point.

Conclusions:

• Orbital-selective Mott phases with interorbital hopping are part of a coherence-incoherence crossover, not a true quantum critical point.
• OSMPs may persist to very low temperatures but are not stable at absolute zero.
• Findings challenge previous theoretical assumptions about OSMP stability.