Quantum Computation using Arrays of N Polar Molecules in Pendular States

Abstract

We investigate several aspects of realizing quantum computation using entangled polar molecules in pendular states. Quantum algorithms typically start from a product state |00⋯0⟩ and we show that up to a negligible error, the ground states of polar molecule arrays can be considered as the unentangled qubit basis state |00⋯0⟩ . This state can be prepared by simply allowing the system to reach thermal equilibrium at low temperature (<1 mK). We also evaluate entanglement, characterized by concurrence of pendular state qubits in dipole arrays as governed by the external electric field, dipole-dipole coupling and number N of molecules in the array. In the parameter regime that we consider for quantum computing, we find that qubit entanglement is modest, typically no greater than 10 , confirming the negligible entanglement in the ground state. We discuss methods for realizing quantum computation in the gate model, measurement-based model, instantaneous quantum polynomial time circuits and the adiabatic model using polar molecules in pendular states.

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][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] , which is not unlike spins.…”

Quantifying entanglement of rotor chains using basis truncation: Application to dipolar endofullerene peapods

“…We explore these two limits in the context of two physically realistic systems-the bare and screened dipole interactions of hydrogen fluoride (HF). Although similar assemblies of polar rotors have recently been examined for use as the basis of a quantum computer, [19][20][21][22] in the present work, we include all the rotational degrees of freedom and do not truncate the system to a qubit representation.…”

EPR steering of polar molecules in pendular states and their dynamics under intrinsic decoherence

“…[27][28][29] As a consequence, the electric dipole moments of ultracold polar molecules, trapped in a 1D optical lattice and coupled by a dipole-dipole interaction, can be chosen as a candidate carrier for quantum computation. 30,31 We note that Wei et al 32,34 evaluated the entanglement of the pendular qubit states for coupled polar molecules, Zhu et al 35 put forward an approach to realize basic quantum logic gates using polar molecules in pendular states, and others have undertaken some research on the physical characteristics of the polar molecules in various external elds. [36][37][38][39][40][41] However, to our knowledge, until now studies have seldom involved the EPR steering of polar molecules in pendular states.…”