Influence of the nature of confinement on the melting of Wigner molecules in quantum dots

Abstract

We analyze the quantum melting of two-dimensional Wigner molecules (WM) in confined geometries with distinct symmetries and compare it with corresponding thermal melting. Our findings unfold complementary mechanisms that drive the quantum and thermal crossovers in a WM and show that the symmetry of the confinement plays no significant role in determining the quantum crossover scale $n_X$. This is because the zero-point motion screens the boundary effects within short distances. The phase diagram as a function of thermal and quantum fluctuations determined from independent criteria is unique, and shows "melting" from the WM to both the classical and quantum "liquids." An intriguing signature of weakening liquidity with increasing temperature, $T$, is found in the extreme quantum regime. The crossover is associated with production of defects. However, these defects appear to play distinct roles in driving the quantum and thermal "melting." Our study will help comprehending melting in a variety of experimental traps - from quantum dots to complex plasma.

14 pages, 9 figures

References in corpus (8)

• Disclinations, dislocations and continuous defects: a reappraisal
• Quantum phase transition in a two-dimensional system of dipoles
• Incipient Wigner Localization in Circular Quantum Dots
• Melting of trapped few particle systems
• Interaction-Induced Strong Localization in Quantum Dots
• Spin and Conductance-Peak-Spacing Distributions in Large Quantum Dots: A Density Functional Theory Study
• Mesoscopic Coulomb Supersolid
• Interaction Effects in the Mesoscopic Regime: A Quantum Monte Carlo Study of Irregular Quantum Dots

Cited by in corpus (5)

• Dynamics of Magnus Dominated Particle Clusters, Collisions, Pinning and Ratchets
• Ab initio Path Integral Monte Carlo Simulations of Quantum Dipole Systems in Traps: Superfluidity, Quantum Statistics, and Structural Properties
• Analysis of vibrational normal modes for Coulomb clusters
• Static and Dynamic Properties of Two Dimensional Coulomb Clusters
• Spatio-temporal correlations in Wigner molecules