1 / 17

Composite Fermion Groundstate of  Rashba Spin-Orbit Bosons

Composite Fermion Groundstate of  Rashba Spin-Orbit Bosons. Alex Kamenev. Fine Theoretical Physics Institute, School of Physics & Astronomy, University of Minnesota. Tigran Sedrakyan Leonid Glazman. ArXiv1208.6266. Chernogolovka QD2012. Motivation.

toril
Download Presentation

Composite Fermion Groundstate of  Rashba Spin-Orbit Bosons

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Composite Fermion Groundstate of  Rashba Spin-Orbit Bosons Alex Kamenev Fine Theoretical Physics Institute, School of Physics & Astronomy, University of Minnesota Tigran Sedrakyan Leonid Glazman ArXiv1208.6266 Chernogolovka QD2012

  2. Motivation Four-level ring coupling scheme in 87Rb involving hyperfine states |F,mF> Raman-coupled by a total of five lasers marked σ1, σ2, σ3, π1, and π2 Spin-orbit coupling constant

  3. Rashba spin-orbit-coupling Rotation + two discrete symmetries time-reversal parity

  4. Bose-Einstein condensates of Rashba bosons Spin-density wave TRSB Interaction Hamiltonian: density operators Chunji Wang, Chao Gao, Chao-Ming Jian, and HuiZhai, PRL 105, 160403 (2010)

  5. Chemical Potential: Spin-orbit coupling constant Estimate chemical potential: Near the band bottom, the density of states diverges as As in 1D! density However, let us look at Rashbafermions:

  6. Reminder: spinless 1D model Tonks-Girardeau limit mean-field bosons spinless fermions exact bosons Lieb - Liniger 1963

  7. Can one Fermionize Rashba Bosons? Yes, but… • Particles have spin • The system is 2D not 1D

  8. Fermions with spin do interact Berg, Rudner, and Kivelson, (2012) Hartree Fock Variational Fermi surface minimizing w.r.t.

  9. Self-consistent Hartree-Fock for Rashba fermions nematic fermions mean-field bosons Berg, Rudner, and Kivelson, (2012) nematic state Elliptic Fermi surface at small density:

  10. Fermionization in 2D? Chern-Simons! Chern-Simons phase bosonic wave function fermionic wave function • (plus/minus) One flux quantum per particle • Broken parity P • Higher spin components are uniquely determined by the projectionon the lower Rashba brunch • Fermionic wave function is Slater determinant, minimizing kinetic and interaction energy

  11. Chern-Simons magnetic Field mean-field approximation Particles with the cyclotron mass: in a uniform magnetic field:

  12. Integer Quantum Hall State Landau levels: Particles with the cyclotron mass: in a uniform magnetic field: One flux quanta per particle, thus n=1 filling factor: IQHE • Gapped bulk and chiral edge mode: interacting topological insulator

  13. Phase Diagram chemical potential Bose Condensate broken R and T Spin-Density Wave broken R broken R, T and P Composite Fermions spin anisotropic interaction

  14. Phase Separation phase separation total energy per volume Bose condensate composite fermions

  15. Rashba Bosons in a Harmonic Trap condensate composite fermions • high density Bose condensate in the middle and low density composite fermions in the periphery

  16. Conclusions • At low density Rashba bosons exhibit Composite Fermion groundstate • CF state breaks R, T and P symmetries • CF state is gaped in the bulk, but supports gapless edge mode, realizing interacting topological insulator • CF equation of state: • There is an interval of densities where CF coexists with the Bose condensate • In a trap the low-density CF fraction is pushed to the edges of the trap

  17. Lattice Model In a vicinity of K and K’ points in the Brillouin zone:

More Related