اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدDynamical behavior of the entanglement, purity and energy between atomic qubits in motion under the influence of thermal environment
42
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The entanglement, purity and energy of two isolated two-level atoms which are initially prepared in Bell state and each interacts with a thermal cavity field are investigated by considering the atomic motion and the field-mode structure. We achieve the analytical solutions of the atomic qubits by using the algebraic dynamical approach and the influences of the field-mode structure parameter, the strength of the thermal field and the detuning on the entanglement, purity and energy are discussed. We also investigate the state evolution of the atomic qubits based on the entanglement-purity-energy diagrams. Our results show that the disentanglement process of the atomic qubits accompanies by excitations transferring from atomic subsystem to cavity field modes and atomic state from a pure state convert to the mixed states.
قيم البحث
اقرأ أيضاً
A theoretical framework to investigate the time evolution of the quantum entanglement due to the dynamical Lamb effect between $N$ superconducting qubits coupled to a coplanar waveguide in the presence of different sources of dissipation is developed
. We quantitatively analyze the case of $N=2$ and $3$ qubits under the assumptions of single switching of the coupling and absence of dissipation within a perturbative approach. The same systems are analyzed for the general case of periodic switching of the coupling in the presence of dissipation via numerical calculations. Different measures of entanglement compatible with mixed states are adopted. It is demonstrated that the different measures show different level of details of the latter. The concurrence and the negativity are obtained in the two qubits case, the three-$pi$ and the negativity in the three qubits case. It is shown that time-dependent Greenberger-Horne-Zeilinger states can be created even in presence of dissipation. To maximize the quantum entanglement between the qubits, the effects of tuning several parameters of the system are investigated.
Quantum entanglement is the central resource behind applications in quantum information science, from quantum computers and simulators of complex quantum systems to metrology and secure communication. All of these applications require the quantum con
trol of large networks of quantum bits (qubits) to realize gains and speedups over conventional devices. However, propagating quantum entanglement generally becomes difficult or impossible as the system grows in size, owing to the inevitable decoherence from the complexity of connections between the qubits and increased couplings to the environment. Here, we demonstrate the first step in a modular approach to scaling entanglement by utilizing a hierarchy of quantum buses on a collection of three atomic ion qubits stored in two remote ion trap modules. Entanglement within a module is achieved with deterministic near-field interactions through phonons, and remote entanglement between modules is achieved through a probabilistic interaction through photons. This minimal system allows us to address generic issues in synchronization and scalability of entanglement with multiple buses, while pointing the way toward a modular large-scale quantum computer architecture that promises less spectral crowding and less decoherence. We generate this modular entanglement faster than the observed qubit decoherence rate, thus the system can be scaled to much larger dimensions by adding more modules.
Exploring an analytical expression for the convex roof of the pure state squared concurrence for rank 2 mixed states the entanglement of a system of three particles under decoherence is studied, using the monogamy inequality for mixed states and the
residual entanglement obtained from it. The monogamy inequality is investigated both for the concurrence and the negativity in the case of local independent phase damping channel acting on generalized GHZ states of three particles and the local independent amplitude damping channel acting on generalized W state of three particles. It is shown that the bipartite entanglement between one qubit and the rest has a qualitative similar behavior to the entanglement between individual qubits, and that the residual entanglement in terms of the negativity cannot be a good entanglement measure for mixed states, since it can increase under local decoherence.
We demonstrate the use of an optical frequency comb to coherently control and entangle atomic qubits. A train of off-resonant ultrafast laser pulses is used to efficiently and coherently transfer population between electronic and vibrational states o
f trapped atomic ions and implement an entangling quantum logic gate with high fidelity. This technique can be extended to the high field regime where operations can be performed faster than the trap frequency. This general approach can be applied to more complex quantum systems, such as large collections of interacting atoms or molecules.
The fate of entanglement of spins for two heavy constituents of a bound state moving in a strong laser field is analyzed within the semiclassical approach. The bound state motion as a whole is considered classically beyond the dipole approximation an
d taking into account the magnetic field effect by using the exact solution to the Newton equation. At the same time the evolution of constituent spins under the laser influence is studied quantum mechanically. The spin density matrix is determined as solution to the von Neumann equation with the effective Hamiltonian, describing spin-laser interaction along the bound state classical trajectory. Based on the solution, the dynamics of concurrence of spins is calculated for the maximally entangled Werner states as well as for an initially uncorrelated state.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
