25 May 2016

Potential qubits maintain quantum coherence outside a crystal

Illustration of coherent coupling in an Mn3 tetramer, emphasizing the connectivity, orientation of the Mn3 planes (blue triangles) and the Jahn–Teller axes (green bonds). Illustration of coherent coupling in an Mn3 tetramer, emphasizing the connectivity, orientation of the Mn3 planes (blue triangles) and the Jahn–Teller axes (green bonds).

This approach to building “qubits” could be a promising tool for developing quantum computers.

First, some background

Single-molecule magnets (SMMs) are molecules that can function as nanoscale magnetic particles. Recent studies suggest they could also one day be used as qubits, the computational unit of tomorrow’s quantum computers. In order to relay quantum information between them, a property known as quantum coherence, these SMMs should ideally be linked to each other chemically.

What did scientists discover?

Previous research revealed quantum coherence between SMM pairs, but only in certain crystalline materials where molecules were forced into close contact, rather than being chemically bonded to each other. In this new experiment, scientists examined SMMs made of three manganese atoms (Mn3) that were chemically linked, forming so-called supramolecular aggregates of either two or four Mn3 molecules (dimers or tetramers, respectively). What they observed using Electron Magnetic Resonance (EMR) was that these molecules exhibited coherent coupling even in solution form, demonstrating for the first time that the supramolecular aggregates stay in tact and maintain quantum coherence outside a crystal.

Why is this important?

SMMs could one day be used as qubits, and recent research [Nature 531, 348 (2016)] has demonstrated they can maintain coherence long enough to work this way. This research shows that supramolecular chemistry allows complex molecules to assemble in multi-qubit arrays, making it a promising tool for building multi-qubit devices. If this approach can be scaled-up, it could lead to the realization of a quantum computer.

Who did the research?

T. N.. Nguyen1, W. Wernsdorfer2, T. Ghosh1, M. Shiddiq3, K. A. Abboud2, S. Hill3 and G. Christou1

1University of Florida; 2Louis Néel Lab, Grenoble; 3MagLab and Florida State University

Why did they need the MagLab?

THE TOOLS THEY USED

This research was conducted in the 17 T and Broadband MVNA in the MagLab's EMR Facility.

The Mn3 molecules used in this study possess electronic structures that can only be characterized using high magnetic fields and high EMR frequencies, instrumentation that is only available at the MagLab.

Details for scientists

Funding

This research was funded by the following grants: G.S. Boebinger (NSF DMR-1157490); Hill (NSF DMR-1309463); Christou (NSF DMR-1213030)


For more information, contact Stephen Hill.

Details

  • Research Area: Chemistry, Magnetism and Magnetic Materials, Qubits and Quantum Entanglement
  • Research Initiatives: Materials
  • Facility / Program: EMR
  • Year: 2016
Last modified on 31 May 2016