Quantum Computation using Arrays of N Polar Molecules in Pendular States

Area of Science:

• Quantum Information Science
• Molecular Physics
• Condensed Matter Physics

Background:

• Quantum computation requires initializing qubits in a well-defined, unentangled state, typically |00⋯0⟩.
• Polar molecules in pendular states offer a potential platform for quantum computing due to controllable interactions.

Purpose of the Study:

• To investigate the feasibility of using polar molecules in pendular states for quantum computation.
• To determine the entanglement properties of these molecular arrays in relevant parameter regimes.
• To explore different quantum computing models implementable with this system.

Main Methods:

• Analysis of the ground state properties of polar molecule arrays.
• Calculation of qubit entanglement using concurrence.
• Evaluation of system parameters including electric field, dipole-dipole coupling, and molecule number (N).

Main Results:

• The ground state of polar molecule arrays approximates the |00⋯0⟩ qubit basis state with negligible error.
• Qubit entanglement in the considered parameter regime for quantum computing is modest (≤10⁻⁴).
• The system can be prepared in the desired initial state by reaching thermal equilibrium at low temperatures (<1 mK).

Conclusions:

• Polar molecules in pendular states are a viable candidate for quantum computation initialization.
• The low entanglement in the ground state is advantageous for building quantum processors.
• Various quantum computing models, including gate-based, measurement-based, and adiabatic, can potentially be realized.