Sub-millisecond Entanglement and iSWAP Gate between Molecular Qubits

• URL: http://arxiv.org/abs/2406.15345v1
• Date: Fri, 21 Jun 2024 17:56:42 GMT
• Title: Sub-millisecond Entanglement and iSWAP Gate between Molecular Qubits
• Authors: Lewis R. B. Picard, Annie J. Park, Gabriel E. Patenotte, Samuel Gebretsadkan, David Wellnitz, Ana Maria Rey, Kang-Kuen Ni,
• Abstract summary: Trapped polar molecules have been proposed as a promising quantum computing platform. We implement a two-qubit iSWAP gate using individually trapped $X1Sigma+$ NaCs molecules.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Quantum computation (QC) and simulation rely on long-lived qubits with controllable interactions. Early work in quantum computing made use of molecules because of their readily available intramolecular nuclear spin coupling and chemical shifts, along with mature nuclear magnetic resonance techniques. Subsequently, the pursuit of many physical platforms has flourished. Trapped polar molecules have been proposed as a promising quantum computing platform, offering scalability and single-particle addressability while still leveraging inherent complexity and strong couplings of molecules. Recent progress in the single quantum state preparation and coherence of the hyperfine-rotational states of individually trapped molecules allows them to serve as promising qubits, with intermolecular dipolar interactions creating entanglement. However, universal two-qubit gates have not been demonstrated with molecules. Here, we harness intrinsic molecular resources to implement a two-qubit iSWAP gate using individually trapped $X^{1}\Sigma^{+}$ NaCs molecules. We characterize the innate dipolar interaction between rotational states and control its strength by tuning the polarization of the traps. By allowing the molecules to interact for 664 $\mu$s at a distance of 1.9 $\mu$m, we create a maximally entangled Bell state with a fidelity of 94(3)\%, following postselection to remove trials with empty traps. Using motion-rotation coupling, we measure residual excitation of the lowest few motional states along the axial trapping direction and find them to be the primary source of decoherence. Finally, we identify two non-interacting hyperfine states within the ground rotational level in which we encode a qubit. The interaction is toggled by transferring between interacting and non-interacting states to realize an iSWAP gate. We verify the gate performance by measuring its logical truth table.

Related papers

• Long-lived entanglement of molecules in magic-wavelength optical tweezers [41.94295877935867]
  We present the first realisation of a microwave-driven entangling gate between two molecules. We show that the magic-wavelength trap preserves the entanglement, with no measurable decay over 0.5 s. The extension of precise quantum control to complex molecular systems will allow their additional degrees of freedom to be exploited across many domains of quantum science.
  arXiv  Detail & Related papers  (2024-08-27T09:28:56Z)
• Modeling Non-Covalent Interatomic Interactions on a Photonic Quantum Computer [50.24983453990065]
  We show that the cQDO model lends itself naturally to simulation on a photonic quantum computer. We calculate the binding energy curve of diatomic systems by leveraging Xanadu's Strawberry Fields photonics library. Remarkably, we find that two coupled bosonic QDOs exhibit a stable bond.
  arXiv  Detail & Related papers  (2023-06-14T14:44:12Z)
• Dipolar spin-exchange and entanglement between molecules in an optical tweezer array [0.0]
  Ultracold polar molecules are promising candidate qubits for quantum computing. Using a molecular optical tweezer array, single molecules can be moved and separately addressed for qubit operations. We demonstrate a two-qubit gate to generate entanglement deterministically, an essential resource for all quantum information applications.
  arXiv  Detail & Related papers  (2022-11-17T18:53:42Z)
• Computational Insights into Electronic Excitations, Spin-Orbit Coupling Effects, and Spin Decoherence in Cr(IV)-based Molecular Qubits [63.18666008322476]
  We provide insights into key properties of Cr(IV)-based molecules aimed at assisting chemical design of efficient molecular qubits. We find that the sign of the uniaxial zero-field splitting (ZFS) parameter is negative for all considered molecules. We quantify (super)hyperfine coupling to the $53$Cr nuclear spin and to the $13C and $1H nuclear spins.
  arXiv  Detail & Related papers  (2022-05-01T01:23:10Z)
• Electrical two-qubit gates within a pair of clock-qubit magnetic molecules [59.45414406974091]
  Enhanced coherence in HoW$_10$ molecular spin qubits has been demonstrated by use of Clock Transitions (CTs) We explore the possibility of employing the electric field to effectangling two-qubit quantum gates among two neighbouring CT-protected HoW$_10$ qubits within a diluted crystal.
  arXiv  Detail & Related papers  (2022-04-20T16:27:24Z)
• Quantum computation in a hybrid array of molecules and Rydberg atoms [7.425093155951875]
  We show that an array of polar molecules interacting with Rydberg atoms is a promising hybrid system for scalable quantum computation. Quantum information is stored in long-lived hyperfine or rotational states of molecules. A two-qubit gate based on this interaction has a duration of 1 $mu$s and an achievable fidelity of 99.9%.
  arXiv  Detail & Related papers  (2022-04-08T20:10:36Z)
• Dispersive readout of molecular spin qudits [68.8204255655161]
  We study the physics of a magnetic molecule described by a "giant" spin with multiple $d > 2$ spin states. We derive an expression for the output modes in the dispersive regime of operation. We find that the measurement of the cavity transmission allows to uniquely determine the spin state of the qudits.
  arXiv  Detail & Related papers  (2021-09-29T18:00:09Z)
• Quantum Molecular Unfolding [0.5677685109155078]
  We focus on one specific phase of the molecular docking procedure i.e. Molecular Unfolding (MU) The objective of the MU problem is to find the configuration that maximizes the molecular area, or equivalently, that maximizes the internal distances between atoms inside the molecule. We propose a quantum annealing approach to MU by formulating it as a High-order Unconstrained Binary Optimization (HUBO) Results and performances obtained with quantum annealers are compared with state of art classical solvers.
  arXiv  Detail & Related papers  (2021-07-28T19:28:28Z)
• Computing molecular excited states on a D-Wave quantum annealer [52.5289706853773]
  We demonstrate the use of a D-Wave quantum annealer for the calculation of excited electronic states of molecular systems. These simulations play an important role in a number of areas, such as photovoltaics, semiconductor technology and nanoscience.
  arXiv  Detail & Related papers  (2021-07-01T01:02:17Z)
• Robust storage qubits in ultracold polar molecules [0.0]
  We characterise the dominant mechanisms for decoherence of a storage qubit in an optically trapped ultracold gas of RbCs molecules. Our results unlock the potential of ultracold molecules as a platform for quantum computation.
  arXiv  Detail & Related papers  (2021-03-10T19:20:27Z)
• Quantum coherent spin-electric control in a molecular nanomagnet at clock transitions [57.50861918173065]
  Electrical control of spins at the nanoscale offers architectural advantages in spintronics. Recent demonstrations of electric-field (E-field) sensitivities in molecular spin materials are tantalising. E-field sensitivities reported so far are rather weak, prompting the question of how to design molecules with stronger spin-electric couplings.
  arXiv  Detail & Related papers  (2020-05-03T09:27:31Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.