In the news

Jeremy Levy Co-Edits October 2013 Issue of MRS Bulletin Dedicated to Quantum Computing

  • By Workstudy User
  • 2 December 2013

Materials Issues for Quantum Computation: The new field of quantum computing uses qubits (quantum bits) in place of classical bits to carry out certain types of computation. Physical systems that act as qubits encompass a wide range of technologies, from ions, to local defect states in crystals, and on to microelectronic devices addressable with wire interconnects. Materials issues arise in all of these, and this issue of MRS Bulletin describes how materials challenges and opportunities arise and have been used to make qubit-based quantum circuits using very different materials systems.

Semiconductor Nanocrosses Lay Foundations for Topological Quantum Bits

  • By Workstudy User
  • 17 October 2013

PQI faculty Sergey Frolov co-authors a paper in Nature Nanotechnology on the growth and characterization of high quality semiconductor nanocross structures. These structures are the building blocks for topological quantum bits based on recently discovered Majorana fermions.

These tests should make clear whether or not Majorana’s (and the nanowires that house them) are a suitable base for the so-called topological quantum computer.

Measuring Many-Body Entanglement

  • By Workstudy User
  • 4 September 2012

PQI faculty Andrew Daley and his colleagues have proposed a scheme for the measurement of entanglement in a system of cold atoms in an optical lattice. Entanglement is an important theoretical concept, but was previously thought to be difficult to measure in microscopic many-particle systems. They tackle the problem by asking how one might track the changes in entanglement in a nonequilibrium many-body system.

Their proposal involves an optical lattice created by lasers and filled with bosons: identical copies of a boson chain stored in the lattice are coupled as a potential barrier between them is reduced. After tunneling has occurred, a measurement of how the lattice wells are populated would give the entanglement entropy.