Magnetic qubits as hardware for quantum computers

J. Tejada*, E. M. Chudnovsky, E. Del Barco, J. M. Hernandez, T. P. Spiller

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

We propose two potential realisations for quantum bits based on nanometre scale magnetic particles of large spin S and high anisotropy molecular clusters. In case (1) the bit-value basis states |0> and |1> are the ground and first excited spin states S z = S and S-1, separated by an energy gap given by the ferromagnetic resonance (FMR) frequency. In case (2), when there is significant tunnelling through the anisotropy barrier, the qubit states correspond to the symmetric, |0>, and antisymmetric, |1>, combinations of the two-fold degenerate ground state S z = ± S. In each case the temperature of operation must be low compared to the energy gap, Δ, between the states |0> and |1>. The gap Δ in case (2) can be controlled with an external magnetic field perpendicular to the easy axis of the molecular cluster. The states of different molecular clusters and magnetic particles may be entangled by connecting them by superconducting lines with Josephson switches, leading to the potential for quantum computing hardware.

Original languageEnglish
JournalHP Laboratories Technical Report
Issue number87
Publication statusPublished - 1 Jul 2000

Keywords

  • Magnetic clusters
  • Magnetic particles
  • Quantum computing
  • Qubits

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