Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:cond-mat/0308113 · Physical Review Letters

Optical Detection of Fractional Particle Number in an Atomic Fermi-Dirac Gas

Juha Javanainen, Janne Ruostekoski

Published Oct 8, 2003• 53 citations
arXivHTMLPDF

Abstract

We study theoretically a Fermi-Dirac atomic gas in a one-dimensional optical lattice coupled to a coherent electromagnetic field with a topologically nontrivial soliton phase profile. We argue that the resulting fractional eigenvalues of the particle number operator can be detected via light scattering. This could be a truly quantum mechanical measurement of particle number fractionalization in a dilute atomic gas.

DOI
10.1103/physrevlett.91.150404

Related papers

Manipulating atoms in an optical lattice: Fractional fermion number and its optical quantum measurement

Janne Ruostekoski, Juha Javanainen, Gerald V. Dunne

We provide a detailed analysis of our previously proposed scheme [J. Ruostekoski, G. V. Dunne, and J. Javanainen, Phys. Rev. Lett. 88, 180401 (2002)] to engineer the profile of the hopping amplitudes for atomic gases in a one-dimensional optical lattice so that the particle number becomes fractional. We consider a constructed system of a dilute two-species gas of fermionic atoms where the two components are coupled via a coherent electromagnetic field with a topologically nontrivial phase profile. We show both analytically and numerically how the resulting atomic Hamiltonian in a prepared dimerized optical lattice with a defect in the pattern of alternating hopping amplitudes exhibits a fractional fermion number. In particular, in the low-energy limit we demonstrate the equivalence of the atomic Hamiltonian to a relativistic Dirac Hamiltonian describing fractionalization in quantum field theory. Expanding on our earlier argument [J. Javanainen and J. Ruostekoski, Phys. Rev. Lett. 91, 150404 (2003)] we show how the fractional eigenvalues of the particle number operator can be detected via light scattering. In particular, we show how scattering of far-off resonant light can convey information about the counting and spin statistics of the atoms in an optical lattice, including state-selective atom density profiles and atom number fluctuations. Optical detection could provide a truly quantum mechanical measurement of the particle number fractionalization in a dilute atomic gas.

arXiv:0709.2187•Physical Review A•Jan 3, 2008•42 citations

Particle Number Fractionalization of an Atomic Fermi-Dirac Gas in an Optical Lattice

Janne Ruostekoski, Gerald V. Dunne, Juha Javanainen

We show that a dilute two-species gas of Fermi-Dirac alkali-metal atoms in a periodic optical lattice may exhibit fractionalization of the particle number when the two components are coupled via a coherent electromagnetic field with a topologically nontrivial phase profile. This results in fractional eigenvalues of the spin operator with vanishing fluctuations. The fractional part can be accurately controlled by modifying the effective detuning of the electromagnetic field.

arXiv:cond-mat/0204122•Physical Review Letters•Apr 17, 2002•126 citations

Particle-number fractionalization of a one-dimensional atomic Fermi gas with synthetic spin-orbit coupling

Dan-Wei Zhang, L.-B. Shao, Zheng‐Yuan Xue +3 more

We propose an experimental scheme to simulate the fractionalization of the particle number by using a one-dimensional spin-orbit-coupled ultracold fermionic gas. The desired spin-orbit coupling, a kinklike potential, and a conjugation-symmetry-breaking mass term are properly constructed by laser-atom interactions, leading to an effective low-energy relativistic Dirac Hamiltonian with a topologically nontrivial background field. The designed system supports a localized soliton excitation with a fractional particle number that is generally irrational and experimentally tunable, providing a direct realization of the celebrated generalized Su-Schrieffer-Heeger model. In addition, we elaborate on how to detect the induced soliton mode with the fractional particle number in the system.

arXiv:1206.5614•Physical Review A•Dec 17, 2012•14 citations

Detecting quantum coherence of Bose gases in optical lattices by scattering light intensity in cavity

Xiaoji Zhou, Xu Xu, Lan Yin +2 more

We propose a new method of detecting quantum coherence of a Bose gas trapped in a one-dimensional optical lattice by measuring the light intensity from Raman scattering in cavity. After pump and displacement process, the intensity or amplitude of scattering light is different for different quantum states of a Bose gas, such as superfluid and Mott-Insulator states. This method can also be useful to detect quantum states of atoms with two components in an optical lattice.

Optics Express•Jul 9, 2010•7 citations

Quantum anomalous Hall phase in a one-dimensional optical lattice

Sheng Liu, L. B. Shao, Qizhe Hou +1 more

We propose to simulate and detect quantum anomalous Hall phase with ultracold atoms in a one-dimensional optical lattice, with the other synthetic dimension being realized by modulating spin-orbit coupling. We show that the system manifests a topologically nontrivial phase with two chiral edge states which can be readily detected in this synthetic two-dimensional system. Moreover, it is interesting that at the phase transition point there is a flat energy band and this system can also be in a topologically nontrivial phase with two Fermi zero modes existing at the boundaries by considering the synthetic dimension as a modulated parameter. We also show how to measure these topological phases experimentally in ultracold atoms. Another model with a random Rashba and Dresselhaus spin-orbit coupling strength is also found to exhibit topological nontrivial phase, and the impact of the disorder to the system is revealed.

Journal of Physics Condensed Matter•Jan 30, 2018•2 citations

Simulation and measurement of the fractional particle number in one-dimensional optical lattices

Dan-Wei Zhang, Feng Mei, Zheng‐Yuan Xue +2 more

We propose a scheme to mimic and directly measure the fractional particle number in a generalized Su-Schrieffer-Heeger model with ultracold fermions in one-dimensional optical lattices. We show that the fractional particle number in this model can be simulated in the momentum-time parameter space in terms of Berry curvature without a spatial domain wall. In this simulation, a hopping modulation is adiabatically tuned to form a kink-type configuration, and the induced current plays the role of an analogous soliton distributing in the time domain such that the mimicked fractional particle number is expressed by the particle transport. Two feasible experimental setups of optical lattices for realizing the required Su-Schrieffer-Heeger Hamiltonian with tunable parameters and time-varying hopping modulation are presented. We also show practical methods for measuring the particle transport in the proposed cold atom systems by numerically calculating the shift in the Wannier center and the center of mass of an atomic cloud.

arXiv:1502.00059•Physical Review A•Jul 10, 2015•22 citations
We study theoretically a Fermi-Dirac atomic gas in a one-dimensional optical lattice coupled to a coherent electromagnetic field with a topologically nontrivial soliton phase profile. We argue that the resulting fractional eigenvalues of the particle number operator can be detected via light scattering. This could be a truly quantum mechanical measurement of particle number fractionalization in a dilute atomic gas.
We provide a detailed analysis of our previously proposed scheme [J. Ruostekoski, G. V. Dunne, and J. Javanainen, Phys. Rev. Lett. 88, 180401 (2002)] to engineer the profile of the hopping amplitudes for atomic gases in a one-dimensional optical lattice so that the particle number becomes fractional. We consider a constructed system of a dilute two-species gas of fermionic atoms where the two components are coupled via a coherent electromagnetic field with a topologically nontrivial phase profile. We show both analytically and numerically how the resulting atomic Hamiltonian in a prepared dimerized optical lattice with a defect in the pattern of alternating hopping amplitudes exhibits a fractional fermion number. In particular, in the low-energy limit we demonstrate the equivalence of the atomic Hamiltonian to a relativistic Dirac Hamiltonian describing fractionalization in quantum field theory. Expanding on our earlier argument [J. Javanainen and J. Ruostekoski, Phys. Rev. Lett. 91, 150404 (2003)] we show how the fractional eigenvalues of the particle number operator can be detected via light scattering. In particular, we show how scattering of far-off resonant light can convey information about the counting and spin statistics of the atoms in an optical lattice, including state-selective atom density profiles and atom number fluctuations. Optical detection could provide a truly quantum mechanical measurement of the particle number fractionalization in a dilute atomic gas.
We propose an experimental scheme to simulate the fractionalization of the particle number by using a one-dimensional spin-orbit-coupled ultracold fermionic gas. The desired spin-orbit coupling, a kinklike potential, and a conjugation-symmetry-breaking mass term are properly constructed by laser-atom interactions, leading to an effective low-energy relativistic Dirac Hamiltonian with a topologically nontrivial background field. The designed system supports a localized soliton excitation with a fractional particle number that is generally irrational and experimentally tunable, providing a direct realization of the celebrated generalized Su-Schrieffer-Heeger model. In addition, we elaborate on how to detect the induced soliton mode with the fractional particle number in the system.
We propose to simulate and detect quantum anomalous Hall phase with ultracold atoms in a one-dimensional optical lattice, with the other synthetic dimension being realized by modulating spin-orbit coupling. We show that the system manifests a topologically nontrivial phase with two chiral edge states which can be readily detected in this synthetic two-dimensional system. Moreover, it is interesting that at the phase transition point there is a flat energy band and this system can also be in a topologically nontrivial phase with two Fermi zero modes existing at the boundaries by considering the synthetic dimension as a modulated parameter. We also show how to measure these topological phases experimentally in ultracold atoms. Another model with a random Rashba and Dresselhaus spin-orbit coupling strength is also found to exhibit topological nontrivial phase, and the impact of the disorder to the system is revealed.
We propose a scheme to mimic and directly measure the fractional particle number in a generalized Su-Schrieffer-Heeger model with ultracold fermions in one-dimensional optical lattices. We show that the fractional particle number in this model can be simulated in the momentum-time parameter space in terms of Berry curvature without a spatial domain wall. In this simulation, a hopping modulation is adiabatically tuned to form a kink-type configuration, and the induced current plays the role of an analogous soliton distributing in the time domain such that the mimicked fractional particle number is expressed by the particle transport. Two feasible experimental setups of optical lattices for realizing the required Su-Schrieffer-Heeger Hamiltonian with tunable parameters and time-varying hopping modulation are presented. We also show practical methods for measuring the particle transport in the proposed cold atom systems by numerically calculating the shift in the Wannier center and the center of mass of an atomic cloud.