GHZ-like states in the Qubit-Qudit Rabi model

Abstract

We study a Rabi type Hamiltonian system in which a qubit and a dd-level quantum system (qudit) are coupled through a common resonator. In the weak and strong coupling limits the spectrum is analysed through suitable perturbative schemes. The analysis show that the presence of the multilevels of the qudit effectively enhance the qubit-qudit interaction. The ground state of the strongly coupled system is found to be of Greenberger-Horne-Zeilinger (GHZ) type. Therefore, despite the qubit-qudit strong coupling, the nature of the specific tripartite entanglement of the GHZ state suppresses the bipartite entanglement. We analyze the system dynamics under quenching and adiabatic switching of the qubit-resonator and qudit-resonator couplings. In the quench case, we found that the non-adiabatic generation of photons in the resonator is enhanced by the number of levels in the qudit. The adiabatic control represents a possible route for preparation of GHZ states. Our analysis provides relevant information for future studies on coherent state transfer in qubit-qudit systems.

Quantum synchronization: insights and applications to quantum information processing

“…MRL (2) 0.12 0.13 0.14 0.15 0.16 0.17 assess potential applications of our proposed measures in real-world quantum systems.…”

“…Note that phase coherence S pcoh and M RL (1) is zero when only squeezing is present, which is expected, as these measures reflect the first off-diagonal elements in the density matrix. On the other hand, S peak and M RL (2) scale almost linearly with squeezing.…”

“…From both plots of Fig. 3.10, we can tell the connections between these measures: CFI, QFI and M RL (2) are highly correlated in their response to the driving. On the other hand, phase coherence S pcoh and M RL (1) exhibit a strong connection, as they (1) and phase coherence are 0 in this case for the same reason as above.…”

“…In this scenario, the two measures (phase coherence S pcoh and M RL (1) ) which are only capable of measuring 1-to-1 synchronization decrease and appears to change almost linearly with increasing squeezing parameter. M RL (2) is a measure dedicated to 2-to-1 synchronization, therefore it is unsurprising that it only provides partial information when single peak is present. This explains why M RL (2) drops to zero at small η and increases linearly afterwards.…”

“…M RL (2) is a measure dedicated to 2-to-1 synchronization, therefore it is unsurprising that it only provides partial information when single peak is present. This explains why M RL (2) drops to zero at small η and increases linearly afterwards. The measurement of S peak lacks the ability to differentiate between two types of synchronization.…”