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:0801.3320 · Open Systems & Information Dynamics

Noise Induced Current in a Double-Well Trap

Sebastiano Anderloni, Fabio Benatti, Roberto Floreanini B

Published Jun 1, 2008• 1 citation
arXivHTMLPDF

Abstract

We study the behaviour of cold atoms trapped in optical double well potentials in the presence of noise, either generated by an external environment or by the trap itself. We show that quite in general the noise can induce a current between the two wells even when tunneling between the two wells is highly suppressed (Mott insulator phase). An engineered environment could provide a test ground for the behaviour of such a current.

DOI
10.1142/s1230161208000134

Related papers

Suppression and enhancement of decoherence in an atomic Josephson junction

Yonathan Japha, Shuyu Zhou, Mark Keil +3 more

We investigate the role of interatomic interactions when a Bose gas, in a double-well potential with a finite tunneling probability (a ‘Bose–Josephson junction’), is exposed to external noise. We examine the rate of decoherence of a system initially in its ground state with equal probability amplitudes in both sites. The noise may induce two kinds of effects: firstly, random shifts in the relative phase or number difference between the two wells and secondly, loss of atoms from the trap. The effects of induced phase fluctuations are mitigated by atom–atom interactions and tunneling, such that the dephasing rate may be suppressed by half its single-atom value. Random fluctuations may also be induced in the population difference between the wells, in which case atom–atom interactions considerably enhance the decoherence rate. A similar scenario is predicted for the case of atom loss, even if the loss rates from the two sites are equal. We find that if the initial state is number-squeezed due to interactions, then the loss process induces population fluctuations that reduce the coherence across the junction. We examine the parameters relevant for these effects in a typical atom chip device, using a simple model of the trapping potential, experimental data, and the theory of magnetic field fluctuations near metallic conductors. These results provide a framework for mapping the dynamical range of barriers engineered for specific applications and set the stage for more complex atom circuits (‘atomtronics’).

arXiv:1511.00173•New Journal of Physics•May 10, 2016•6 citations

Noise-induced interference fringes in trapped ultracold bosonic gases

Sebastiano Anderloni, Fabio Benatti, Roberto Floreanini B +1 more

We study the dynamics of ultracold atoms trapped in optical double-well potentials in presence of noise generated by an external environment. When prepared in a Fock number state, the system shows phase coherence in the averaged density profile obtained using standard absorption image techniques, that disappears in absence of noise. This effect indicates that also in many-body systems an external environment may enhance quantum coherence, instead of destroying it.

arXiv:0811.2857•Physical Review A•Nov 21, 2008•2 citations

Coherent wave packet dynamics in a double-well potential in cavity

Zheng Li, Gang Li, Ming‐Song Ding +2 more

We investigate the coherent wave packet dynamics of a two-level atom trapped in a symmetric double-well potential in a near-resonance cavity. Prepared on one side of the double-well potential, the atom wave packet oscillates between the left and right wells, while recoil induced by the emitted photon from the atom entangles the atomic internal and external degrees of freedom. The collapse and revival of the tunneling occurs. Adjusting the width of the wave packets, one can modify the tunneling frequency and suppress the tunneling.

International Journal of Modern Physics B•Oct 6, 2017•0 citations

Macroscopic tunneling, decoherence and noise-induced activation

Fernando C. Lombardo, Diana Monteoliva, Paula I. Villar

Abstract. We study the effects of the environment at zero temperature on tunneling in an open system described by a static double-well potential. We show that the evolution of the system in an initial Schrödinger cat state, can be summarized in terms of three main physical phenomena, namely decoherence, quantum tunneling and noise-induced activation. Using large-scale numerical simulations, we obtain a detailed picture of the main stages of the evolution and of the relevant dynamical processes. The tunneling of a particle through a potential barrier is a fundamental effect in quantum mechanics. Macroscopic quantum tunneling can be associated with the tunneling of a many-body wavefunction through a potential barrier, and therefore provides a more stringent test of the validity of quantum mechanics than one particle case. One place where the study of macroscopic quantum tunneling is experimentally accesible is in the tunneling of a Bose-Einstein condensate (BEC) out of an optical trap. These systems have a controllable number of atoms and hence straddle the boundary between microscopic and macroscopic, and hence between quantum and classical systems. Proposals to perform interference experiments using confined atoms

•Jan 1, 2006•1 citation

Electromagnetically Induced Transparency in a Double Well Atomic Josephson Junction

James Owen Weatherall, Christopher P. Search

Electromagnetically induced transparency is an important tool for controlling light propagation and nonlinear wave mixing in atomic gases with potential applications ranging from quantum computing to table top tests of general relativity.Here we consider electromagnetically induced transparency in an atomic Bose-Einstein condensate trapped in a double well potential.One well is prepared as in standard electromagnetically induced transparency with a weak probe laser and control laser in a Λ configuration while tunneling between the wells provides a coherent coupling between identical electronic states in the two wells leading to the formation of spatially delocalized inter-well dressed states.The macroscopic inter-well coherence of the Bose-Einstein condensate wave function qualitatively modifies the normal electromagnetically induced transparency linear susceptibility and leads to the formation of additional absorption resonances and larger dispersion than electromagnetically induced transparency.We show that these new resonances can be interpreted in terms of the inter-well dressed states and the formation of a novel type of dark state involving the control laser and the inter-well tunneling.

Acta Physica Polonica A•Oct 1, 2009•0 citations

Coherent control of atomic spin currents in a double well

H. T. Ng, Shih‐I Chu

We propose a method for controlling the atomic currents of a two-component Bose-Einstein condensate in a double well by applying an external field to the atoms in one of the potential wells. We study the ground-state properties of the system and show that the directions of spin currents and net-particle tunneling can be manipulated by adiabatically varying the coupling strength between the atoms and the field. This system can be used to study spin and tunneling phenomena across a wide range of interaction parameters. In addition, spin-squeezed states can be generated. It is useful for quantum information processing and quantum metrology.

arXiv:1111.0529•Physical Review A•Feb 27, 2012•6 citations
We study the behaviour of cold atoms trapped in optical double well potentials in the presence of noise, either generated by an external environment or by the trap itself. We show that quite in general the noise can induce a current between the two wells even when tunneling between the two wells is highly suppressed (Mott insulator phase). An engineered environment could provide a test ground for the behaviour of such a current.
We investigate the role of interatomic interactions when a Bose gas, in a double-well potential with a finite tunneling probability (a ‘Bose–Josephson junction’), is exposed to external noise. We examine the rate of decoherence of a system initially in its ground state with equal probability amplitudes in both sites. The noise may induce two kinds of effects: firstly, random shifts in the relative phase or number difference between the two wells and secondly, loss of atoms from the trap. The effects of induced phase fluctuations are mitigated by atom–atom interactions and tunneling, such that the dephasing rate may be suppressed by half its single-atom value. Random fluctuations may also be induced in the population difference between the wells, in which case atom–atom interactions considerably enhance the decoherence rate. A similar scenario is predicted for the case of atom loss, even if the loss rates from the two sites are equal. We find that if the initial state is number-squeezed due to interactions, then the loss process induces population fluctuations that reduce the coherence across the junction. We examine the parameters relevant for these effects in a typical atom chip device, using a simple model of the trapping potential, experimental data, and the theory of magnetic field fluctuations near metallic conductors. These results provide a framework for mapping the dynamical range of barriers engineered for specific applications and set the stage for more complex atom circuits (‘atomtronics’).
We investigate the coherent wave packet dynamics of a two-level atom trapped in a symmetric double-well potential in a near-resonance cavity. Prepared on one side of the double-well potential, the atom wave packet oscillates between the left and right wells, while recoil induced by the emitted photon from the atom entangles the atomic internal and external degrees of freedom. The collapse and revival of the tunneling occurs. Adjusting the width of the wave packets, one can modify the tunneling frequency and suppress the tunneling.
Abstract. We study the effects of the environment at zero temperature on tunneling in an open system described by a static double-well potential. We show that the evolution of the system in an initial Schrödinger cat state, can be summarized in terms of three main physical phenomena, namely decoherence, quantum tunneling and noise-induced activation. Using large-scale numerical simulations, we obtain a detailed picture of the main stages of the evolution and of the relevant dynamical processes. The tunneling of a particle through a potential barrier is a fundamental effect in quantum mechanics. Macroscopic quantum tunneling can be associated with the tunneling of a many-body wavefunction through a potential barrier, and therefore provides a more stringent test of the validity of quantum mechanics than one particle case. One place where the study of macroscopic quantum tunneling is experimentally accesible is in the tunneling of a Bose-Einstein condensate (BEC) out of an optical trap. These systems have a controllable number of atoms and hence straddle the boundary between microscopic and macroscopic, and hence between quantum and classical systems. Proposals to perform interference experiments using confined atoms
Electromagnetically induced transparency is an important tool for controlling light propagation and nonlinear wave mixing in atomic gases with potential applications ranging from quantum computing to table top tests of general relativity.Here we consider electromagnetically induced transparency in an atomic Bose-Einstein condensate trapped in a double well potential.One well is prepared as in standard electromagnetically induced transparency with a weak probe laser and control laser in a Λ configuration while tunneling between the wells provides a coherent coupling between identical electronic states in the two wells leading to the formation of spatially delocalized inter-well dressed states.The macroscopic inter-well coherence of the Bose-Einstein condensate wave function qualitatively modifies the normal electromagnetically induced transparency linear susceptibility and leads to the formation of additional absorption resonances and larger dispersion than electromagnetically induced transparency.We show that these new resonances can be interpreted in terms of the inter-well dressed states and the formation of a novel type of dark state involving the control laser and the inter-well tunneling.
We propose a method for controlling the atomic currents of a two-component Bose-Einstein condensate in a double well by applying an external field to the atoms in one of the potential wells. We study the ground-state properties of the system and show that the directions of spin currents and net-particle tunneling can be manipulated by adiabatically varying the coupling strength between the atoms and the field. This system can be used to study spin and tunneling phenomena across a wide range of interaction parameters. In addition, spin-squeezed states can be generated. It is useful for quantum information processing and quantum metrology.