Quantum Correlations and Coherence of Polar Symmetric Top Molecules in Pendular States

Abstract

We consider two ultracold polar symmetric top molecules coupled by dipole-dipole interaction in an external electric field with appreciable intensity gradient, serving as the physical carrier of quantum information. Each molecule is induced to undergo pendular oscillations under the strong static electric field. Based on the pendular states of polar symmetric top molecules as candidate qubits, we investigate the bipartite quantum correlations of the two polar molecular system for the thermal equilibrium states, characterized by negativity and quantum discord, and then analyze the corresponding coherence, measured by relative entropy and l 1 norm. Furthermore, we also examine the dynamics of the entanglement and coherence of the system in the presence of intrinsic decoherence, and explore the relations of their temporal evolution with various physical system parameters for two different initial Bell states. It is found that quantum correlations and coherence of the two polar molecules in pendular states can be manipulated by adjusting appropriate reduced variables including external electric field, dipole-dipole interaction, ambient temperature and decoherence factor. Our findings could be used for molecular quantum computing based on rotational states.

Realization of Heisenberg models of spin systems with polar molecules in pendular states

“…One potential application of polar molecules is in quantum computing, as originally proposed by DeMille two decades ago [11] . Since then, many aspects and variants have been extensively studied, including for both diatomic linear molecules and symmetric top molecules [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] . For linear molecules, the |00 and |10 pendular states are the most commonly used qubit states [12][13][14][15][16][17][18][19][20][21][22][23][24] .…”

“…For symmetric top molecules, different choices of qubit states have been explored [25,26] . In most cases, the Hamiltonian matrices are complex and no existing model can be used directly.…”

“…Moreover, the internal structure of polar molecules is much richer than that of atoms or spins, allowing much richer physics. Given these unique properties, arrays of polar molecules are considered to be promising platforms for quantum computing and quantum information processing [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] , which is not unlike spins.…”

Non-local correlation dynamics in two-dimensional graphene

“…The dcoherence times for the Milburn master equation have been introduced 42 – 44 . The intrinsic decoherence model has been used to explore quantum information resources dynamics in several real systems as: trapped ion coupled to an optical cavity 44 , single solid state transistors 45 , polar molecules in pendular states 46 , 47 as well as two superconducting charge qubit system 48 .…”

Realization of Heisenberg models of spin systems with polar molecules in pendular states

“…Moreover, the internal structure of polar molecules is much richer than that of atoms or spins, allowing much richer physics. Given these unique properties, arrays of polar molecules are considered to be promising platforms for quantum computing and quantum information processing, 10–26 which is not unlike spins.…”