Macroscopic superpositions in Bose-Josephson junctions: Controlling decoherence due to atom losses

  title={Macroscopic superpositions in Bose-Josephson junctions: Controlling decoherence due to atom losses},
  author={Krzysztof Pawłowski and D Spehner and Anna Minguzzi and G. Ferrini},
  journal={Physical Review A},
We study how macroscopic superpositions of coherent states produced by the nondissipative dynamics of binary mixtures of ultracold atoms are affected by atom losses. We identify different decoherence scenarios for symmetric or asymmetric loss rates and interaction energies in the two modes. In the symmetric case the quantum coherence in the superposition is lost after a single loss event. By tuning appropriately the energies we show that the superposition can be protected, leading to quantum… 

Figures from this paper

Effect of one-, two-, and three-body atom loss processes on superpositions of phase states in Bose-Josephson junctions
In a two-mode Bose-Josephson junction formed by a binary mixture of ultracold atoms, macroscopic superpositions of phase states are produced during the time evolution after a sudden quench to zero of
Superadiabatic generation of cat states in bosonic Josephson junctions under particle losses
We investigate a superadiabatic scheme to produce a cat state in a bosonic Josephson junction in absence and presence of particle losses. The generation scheme is based on shortcuts to adiabaticity
Spin squeezing and Einstein-Podolsky-Rosen entanglement of two bimodal condensates in state-dependent potentials
We propose and analyze a scheme to entangle the collective spin states of two spatially separated bimodal Bose-Einstein condensates. Using a four-mode approximation for the atomic field, we show that
Evolution of entanglement under an Ising-like Hamiltonian with particle losses
We present analytical compact solution for the density matrix and correlation functions of two collective-macroscopic spins evolving via Ising-like Hamiltonian in the presence of particle losses. The
Optimal spin- and planar-quantum squeezing in superpositions of spin coherent states
Richard J. Birrittella, Jason Ziskind, Edwin E. Hach, III, Paul M. Alsing and Christopher C. Gerry Air Force Research Laboratory, Information Directorate, Rome, NY, USA, 13441 Rochester Institute of
Heisenberg-limited Sagnac interferometer with multiparticle states
The Sagnac interferometry has been widely used to measure rotation frequency. Beyond the conventional single-particle Sagnac interferometry, we propose an atomic Sagnac interferometry via
Quantum metrology with spin cat states under dissipation
This scheme provides a realizable way to achieve high-precision measurements via dissipative quantum systems of Bose atoms via spin cat states (a kind of non-Gaussian entangled states in superposition of two quasi-orthogonal spin coherent states) under dissipation.
Achieving Heisenberg-limited metrology with spin cat states via interaction-based readout
Spin cat states are promising candidates for quantum enhanced measurement. Here, we analytically show that, the ultimate measurement precisions of spin cat states approach the Heisenberg limit, where
Quantum trajectories and open many-body quantum systems
The study of open quantum systems – microscopic systems exhibiting quantum coherence that are coupled to their environment – has become increasingly important in the past years, as the ability to
Simultaneous Measurement of dc and ac Magnetic Fields at the Heisenberg Limit
High-precision magnetic field measurement is an ubiquitous issue in physics and a critical task in metrology. Generally, magnetic field has DC and AC components and it is hard to extract both DC and


Noise in Bose Josephson junctions: Decoherence and phase relaxation
Squeezed states and macroscopic superpositions of coherent states have been predicted to be generated dynamically in Bose Josephson junctions. We solve exactly the quantum dynamics of such a junction
Macroscopic superpositions of phase states with Bose-Einstein condensates
Quantum superpositions of macroscopically distinguishable states having distinct phases can be created with a Bose-Einstein condensate trapped in a periodic potential. The experimental signature is
Number squeezing, quantum fluctuations and oscillations in mesoscopic Bose Josephson junctions
Starting from a quantum two-mode Bose-Hubbard Hamiltonian we determine the ground state properties, momentum distribution and dynamical evolution for a Bose Josephson junction realized by an
Effect of phase noise on useful quantum correlations in Bose Josephson junctions
In a two-mode Bose-Josephson junction the dynamics induced by a sudden quench of the tunnel amplitude leads to the periodic formation of entangled states. For instance, squeezed states are formed at
Decoherence due to three-body loss and its effect on the state of a Bose-Einstein condensate.
  • M. Jack
  • Physics, Medicine
    Physical review letters
  • 2002
A Born-Markov master equation is used to investigate the decoherence of the state of a macroscopically occupied mode of a cold atom trap due to three-body loss, and for large numbers of atoms (N>10(4)) theDecoherence time is found to be much faster than the phase-collapse time caused by intratrap atomic collisions.
Background atoms and decoherence in optical lattices
All experiments with ultracold atoms are performed in the presence of background residual gas. With the help of a suitable master equation we investigate a role of these fast atoms on the loss of
Spin squeezing in a bimodal condensate: spatial dynamics and particle losses
We propose an analytical method to study the entangled spatial and spin dynamics of interacting bimodal Bose-Einstein condensates. We show that at particular times during the evolution spatial and
Spin squeezing in Bose—Einstein condensates: Limits imposed by decoherence and non-zero temperature
We consider dynamically generated spin squeezing in interacting bimodal condensates. We show that particle losses and non-zero temperature effects in a multimode theory completely change the scaling
Effect of atom loss on collapse and revivals of phase coherence in small atomic samples
A small atomic sample at a single site of an optical lattice potential is a realization of an anharmonic oscillator with atomic collisions giving rise to the nonlinearity. Due to the atomic
Creation, detection, and decoherence of macroscopic quantum superposition states in double-well Bose-Einstein condensates
We study the possibility of creating many-particle macroscopic quantum superposition (Schr\"odinger cat)--like states by using a Feshbach resonance to reverse the sign of the scattering length of a