  Quantum computation requires efficient long-term storage devices to preserve
quantum states. An attractive candidate for such storage devices is qubits
connected to a common dissipative environment. The common environment gives
rise to persistent entanglements in these qubit systems. Hence these systems
act efficiently as a storage device of entanglement. However, the existence of
a common environment often requires the physical proximity of the qubits and
hence results in direct dipolar coupling between the qubits. In this work, we
investigate the total effect of the dipolar coupling on the environment-induced
entanglement using a recently-proposed fluctuation-regulated quantum master
equation [A. Chakrabarti and R. Bhattacharyya, Phys. Rev. A 97, 063837 (2018)].
We show that nonsecular part of the dipolar coupling results in reduced
entanglement and hence less efficiency of the storage devices. We also discuss
the properties of efficient storage that mitigates the detrimental effects of
the dipolar coupling on the stored entanglement.
