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.

Paul Leu and Kevin Chen Awarded NSF Grant to Develop Improved Solar Cell Manufacturing

  • By Aude Marjolin
  • 14 August 2013

PQI faculty Paul W. Leu and Kevin P. Chen were awarded a $107,498 Early-concept Grants for Exploratory Research (EAGER grant) to develop a new process for the scalable laser manufacturing of more efficient solar cells. 

"We're exploring new structures, called photonic crystals, that are at the wavelength scale or smaller to better trap light within the absorbing region of the solar cell," Dr. Leu explains.

Sergey Frolov and Vincent Liu Receive Kaufman Foundation Inaugural Award

  • By Workstudy User
  • 25 July 2013

The Charles E. Kaufman Foundation, part of The Pittsburgh Foundation, today announced its first series of grants – amounting to almost $1.6 million – to support cutting-edge scientific research at institutions across the State of Pennsylvania.

A New Initiative grant was awarded to Sergey M. Frolov and W. Vincent Liu, who receive $242,310 over two years ($121,155 per year) for research on “Topological Quantum Wire Emulators.”

Massive Dirac Fermions and Hofstadter Butterfly in a van der Waals Heterostructure

  • By Aude Marjolin
  • 21 June 2013

The remarkable transport properties of graphene, such as the high electron mobility, make it a promising material for electronics. However, unlike semiconductors such as silicon, graphene's electronic structure lacks a band gap, and a transistor made out of graphene would not have an “off” state. Ben Hunt and his colleagues modulated the electronic properties of graphene by building a heterostructure consisting of a graphene flake resting on hexagonal boron nitride (hBN), which has the same honeycomb structure as graphene, but consists of alternating boron and nitrogen atoms instead of carbons. The natural mismatch between the graphene and hBN lattices led to a moire pattern with a large wavelength, causing the opening of a band gap, the formation of an elusive fractional quantum Hall state, and, at high magnetic fields, a fractal phenomenon in the electronic structure called the Hofstadter butterfly.

Quantum-Engineered Nanoscale Alloys So Bright They Could Have Potential Medical Applications

  • By Aude Marjolin
  • 14 May 2013

Alloys like bronze and steel have been transformational for centuries, yielding top-of-the-line machines necessary for industry. As scientists move toward nanotechnology, however, the focus has shifted toward creating alloys at the nanometer scale—producing materials with properties unlike their predecessors.

Now, researchers led by PQI faculty Jill Millstone demonstrate that nanometer-scale alloys possess the ability to emit light so bright they could have potential applications in medicine. The findings have been published in the Journal of the American Chemical Society.

Connecting the (Quantum) Dots: Spin Technique Moves Researchers Closer to Creating First Viable High-Speed Quantum Computer

  • By Aude Marjolin
  • 26 February 2013

Recent research offers a new spin on using nanoscale semiconductor structures to build faster computers and electronics. Literally.

Researchers at PQI and Delft University of Technology reveal in the Nature Nanotechnology a new method that better preserves the units necessary to power lightning-fast electronics, known as qubits (pronounced CUE-bits). Hole spins, rather than electron spins, can keep quantum bits in the same physical state up to 10 times longer than before, the report finds.