scholarly journals Intrinsic Decoherence and Recurrences in a Large Ferromagnetic F = 1 Spinor Bose–Einstein Condensate

Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 67
Author(s):  
Juan Carlos Sandoval-Santana ◽  
Roberto Zamora-Zamora ◽  
Rosario Paredes ◽  
Victor Romero-Rochín
Keyword(s):  
Density Matrix ◽  
Coherent States ◽  
Rotational Symmetry ◽  
Einstein Condensate ◽  
Body Density ◽  
Intrinsic Decoherence ◽  
Bose Einstein Condensate ◽  
Spin Interactions ◽  
The One ◽  
Bose Einstein

Decoherence with recurrences appear in the dynamics of the one-body density matrix of an F=1 spinor Bose–Einstein condensate, initially prepared in coherent states, in the presence of an external uniform magnetic field and within the single mode approximation. The phenomenon emerges as a many-body effect of the interplay of the quadratic Zeeman effect, which breaks the rotational symmetry, and the spin-spin interactions. By performing full quantum diagonalizations, a very accurate time evolution of large condensates is analyzed, leading to heuristic analytic expressions for the time dependence of the one-body density matrix, in the weak and strong interacting regimes, for initial coherent states. We are able to find accurate analytical expressions for both the decoherence and the recurrence times, in terms of the number of atoms and strength parameters, which show remarkable differences depending on the strength of the spin-spin interactions. The features of the stationary states in both regimes are also investigated. We discuss the nature of these limits in light of the thermodynamic limit.

scholarly journals Decoherence and Recurrences in a Large Ferromagnetic $F = 1$ Spinor Bose-Einstein Condensate

2020 ◽  
Author(s):  
Victor Romero-Rochin ◽  
Juan Carlos Sandoval-Santana ◽  
Rosario Paredes
Keyword(s):  
Density Matrix ◽  
Rotational Symmetry ◽  
Zeeman Effect ◽  
Single Mode ◽  
Einstein Condensate ◽  
Bose Einstein Condensate ◽  
Spin Interactions ◽  
Analytic Expressions ◽  
The One ◽  
Bose Einstein

Decoherence with recurrences appear in the dynamics of the one-body density matrix of an $F = 1$ spinor Bose-Einstein condensate, initially prepared in coherent states, in the presence of an external uniform magnetic field and within the single mode approximation. The phenomenon emerges as a many-body effect of the interplay of the quadratic Zeeman effect, that breaks the rotational symmetry, and the spin-spin interactions. By performing full quantum diagonalizations very accurate time evolution of large condensates are analyzed, leading to heuristic analytic expressions for the time dependence of the density matrix, in the weak and strong interacting regimes. We are able to find accurate analytical expressions for both the decoherence and the recurrence times, in terms of the number of atoms and strength parameters, that show remarkable differences depending on the strength of the spin-spin interactions. We discuss the nature of these limits in the light of the thermodynamic limit.

A CLASS OF CLOSED SOLUTIONS FOR THE BOGOLIUBOV EXCITATIONS ON SMOOTH GROUND STATE OF A TRAPPED BOSE–EINSTEIN CONDENSATE

2005 ◽  
Vol 19 (15) ◽  
pp. 713-720
Author(s):  
YONG-LI MA ◽  
HAICHEN ZHU
Keyword(s):  
Ground State ◽  
Einstein Condensate ◽  
Zero Energy ◽  
Ground State Wavefunction ◽  
New Class ◽  
Bose Einstein Condensate ◽  
Energy Mode ◽  
The One ◽  
Bose Einstein ◽  
Bogoliubov Excitations

Bogoliubov–de Gennes equations (BdGEs) for collective excitations from a trapped Bose–Einstein condensate described by a spatially smooth ground-state wavefunction can be treated analytically. A new class of closed solutions for the BdGEs is obtained for the one-dimensional (1D) and 3D spherically harmonic traps. The solutions of zero-energy mode of the BdGEs are also provided. The eigenfunctions of the excitations consist of zero-energy mode, zero-quantum-number mode and entire excitation modes when the approximate ground state is a background Bose gas sea.

scholarly journals Spontaneous symmetry breaking in persistent currents of spinor polaritons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Evgeny Sedov ◽  
Sergey Arakelian ◽  
Alexey Kavokin
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Degrees Of Freedom ◽  
Continuous Wave ◽  
Rotational Symmetry ◽  
Einstein Condensate ◽  
Persistent Currents ◽  
Optical Pump ◽  
Bose Einstein Condensate ◽  
Bose Einstein

AbstractWe predict the spontaneous symmetry breaking in a spinor Bose–Einstein condensate of exciton-polaritons (polaritons) caused by the coupling of its spin and orbital degrees of freedom. We study a polariton condensate trapped in a ring-shaped effective potential with a broken rotational symmetry. We propose a realistic scheme of generating controllable spinor azimuthal persistent currents of polaritons in the trap under the continuous wave optical pump. We propose a new type of half-quantum circulating states in a spinor system characterized by azimuthal currents in both circular polarizations and a vortex in only one of the polarizations. The spontaneous symmetry breaking in the spinor polariton condensate that consists in the switching from co-winding to opposite-winding currents in opposite spin states is revealed. It is characterized by the change of the average orbital angular momentum of the condensate from zero to non-zero values. The radial displacement of the pump spot and the polarization of the pump act as the control parameters. The considered system exhibits a fundamental similarity to a superconducting flux qubit, which makes it highly promising for applications in quantum computing.

scholarly journals TWO-PHOTON NONLINEAR SPECTROSCOPY OF PERIODICALLY TRAPPED ULTRACOLD ATOMS IN A CAVITY

2011 ◽  
Vol 25 (13) ◽  
pp. 1737-1746
Author(s):  
TARUN KUMAR ◽  
ARANYA B. BHATTACHERJEE ◽  
MANMOHAN
Keyword(s):  
Ultracold Atoms ◽  
Einstein Condensate ◽  
Nonlinear Spectroscopy ◽  
Transmission Spectra ◽  
Two Photon ◽  
Photon Transition ◽  
Cavity Transmission ◽  
Bose Einstein Condensate ◽  
The One ◽  
Bose Einstein

We study the transmission spectra of a Bose Einstein condensate (BEC) confined in an optical lattice interacting with two modes of a cavity via nonlinear two-photon transition. In particular, we show that the one-photon and two-photon cavity transmission spectra of a BEC are different. We found that when the BEC is in the Mott state, the usual normal mode splitting present in the one-photon transition is missing in the two-photon interaction. When the BEC is in the superfluid state, the transmission spectrum shows the usual multiple lorentzian structure. However the separation between the lorentzians for the two-photon case is much larger than that for the one-photon case. This study could form the basis for nondestructive high resolution Rydberg spectroscopy of ultracold atoms or two-photon spectroscopy of a gas of ultracold atomic hydrogen.

scholarly journals Soliton Solutions and Collisions for the Multicomponent Gross–Pitaevskii Equation in Spinor Bose–Einstein Condensates

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ming Wang ◽  
Guo-Liang He
Keyword(s):  
Soliton Solutions ◽  
Auxiliary Function ◽  
Einstein Condensate ◽  
Polarization Parameter ◽  
One Dimension ◽  
Pitaevskii Equation ◽  
Bose Einstein Condensate ◽  
The One ◽  
Bose Einstein ◽  
Two Peaks

In this paper, we investigate a five-component Gross–Pitaevskii equation, which is demonstrated to describe the dynamics of an F=2 spinor Bose–Einstein condensate in one dimension. By employing the Hirota method with an auxiliary function, we obtain the explicit bright one- and two-soliton solutions for the equation via symbolic computation. With the choice of polarization parameter and spin density, the one-soliton solutions are divided into four types: one-peak solitons in the ferromagnetic and cyclic states and one- and two-peak solitons in the polar states. For the former two, solitons share the similar shape of one peak in all components. Solitons in the polar states have the one- or two-peak profiles, and the separated distance between two peaks is inversely proportional to the value of polarization parameter. Based on the asymptotic analysis, we analyze the collisions between two solitons in the same and different states.

scholarly journals INFLUENCE OF INTRINSIC DECOHERENCE ON NONCLASSICAL PROPERTIES OF THE OUTPUT OF A BOSE–EINSTEIN CONDENSATE

2005 ◽  
Vol 19 (01n02) ◽  
pp. 35-46
Author(s):  
SHANG-BIN LI ◽  
JING-BO XU
Keyword(s):  
Einstein Condensate ◽  
Atom Laser ◽  
Intrinsic Decoherence ◽  
Squeezing Property ◽  
Bose Einstein Condensate ◽  
Nonclassical Properties ◽  
Bose Einstein

We investigate nonclassical properties of the output of a Bose–Einstein condensate in Milburn's model of intrinsic decoherence. It is shown that the squeezing property of the atom laser is suppressed due to decoherence. Nevertheless, if some very special conditions were satisfied, the squeezing properties of atom laser could be robust against the decoherence.

QUANTUM TELEPORTATION FROM LIGHT TO ATOMIC BOSE–EINSTEIN CONDENSATE

2010 ◽  
Vol 24 (10) ◽  
pp. 937-944 ◽  
Author(s):  
YU GUO ◽  
RONG-SHENG QU
Keyword(s):  
Coherent State ◽  
Quantum Teleportation ◽  
Coherent States ◽  
Einstein Condensate ◽  
Kerr Medium ◽  
Optical Scheme ◽  
Optical Elements ◽  
Beam Splitters ◽  
Bose Einstein Condensate ◽  
Bose Einstein

An optical scheme of the quantum teleportation of superposed coherent states from light pulse to the atoms in Bose–Einstein condensate in terms of optical elements is presented. Beam splitters, photodetectors, cross-Kerr medium, and coherent state sources are needed in this scheme. The probability of successful teleportation is also obtained.

Sign in / Sign up

Export Citation Format

Share Document