International Journal of Physics | Vol. 1, No. 1, January 2010 | pp. 1–8
Research Article
Title: Quantum Phase Transitions in Ultra-Cold Fermi Gases with Tunable Interactions
Names of Authors: A. K. Sharma¹, B. R. Mehta², C. H. Liu³
Authors’ Affiliations: ¹Department of Physics, Indian Institute of Technology, New Delhi, India; ²Department of Applied Physics, University of Tokyo, Tokyo, Japan; ³Department of Physics, National University of Singapore, Singapore
Abstract: We investigate the quantum phase transitions in ultra-cold Fermi gases near a Feshbach resonance using a multi-channel functional renormalization group approach. By tuning the scattering length a from weak to strong coupling regimes, we evaluate the critical chemical potential mu_c and the pairing gap delta at T = 0 K. Our results indicate a smooth crossover from the Bardeen-Cooper-Schrieffer state to a Bose-Einstein condensate, exhibiting a non-monotonic behavior in the collective excitation frequency omega_b. The calculated critical exponent nu = 0.67 ± 0.03 aligns well with the universal scaling predictions for the unitary Fermi gas. Furthermore, we analyze the thermodynamic stability via the compressibility kappa and find suppressed fluctuations near the critical magnetic field B_c = 834.2 G. These findings provide robust theoretical benchmarks for ongoing optical lattice experiments involving lithium-6 and potassium-40 atomic mixtures.
Keywords: Ultra-cold gases, Feshbach resonance, Quantum phase transition, Renormalization group, Fermi-Bose crossover
Manuscript Timeline: Received 10 October 2009, Revised 15 November 2009, Accepted 02 December 2009, Published 05 January 2010
Citation: Sharma, A. K., Mehta, B. R., & Liu, C. H. (2010). Quantum Phase Transitions in Ultra-Cold Fermi Gases with Tunable Interactions. International Journal of Physics, 1(1), 1–8. DOI: 10.46882/2010/IJP/000001
Subscribe to read the full article: https://internationalscholarsjournals.org/subscribe-to-read