News


New Era in Thermal Scanning Probe Lithography

  • By Burcu Ozden
  • 15 November 2017

Tevis Jacobs and his collaborators from IBM and SwissLitho were achieved sub-10 nanometer feature size in Silicon using thermal scanning probe lithography. In this work, they  the t-SPL parameters that influence high-resolution patterning on the transfer stack and demonstrate that sub-15 nm half-pitch resolution patterning and transfer by t-SPL are feasible. They found that the resolution in t-SPL is limited by the extent of the plastic zone in thermo-mechanical indentation on the pattern transfer stack because, at temperatures approaching the resist’s decomposition temperature, the line shape widens, reducing the achievable resolution. They achieved reliable transfer of patterned dense lines down to 14 nm half-pitch and in the best case 11 nm half-pitch. Furthermore, evidently they showed that an enhanced resolution below 10 nm half-pitch might be possible on a mechanically different transfer stack.


Science2017 Poster Award Winners

  • By Leena Aggarwal
  • 15 November 2017

Congratulations to the Science2017 Poster Award Winners!

Jierui Liang (Fullerton group, SSOE Chemical and Petroleum Engineering) won the grand prize award ($1,000 travel award plus an iPad).

Minh Nguyen Vo (Johnson Group, SSOE Chemical and Petroleum Engineering), Olivia Lanes (Hatridge Group, Pitt Physics), Scott Crawford (Millstone Group, Pitt Chemistry), Maxwell Li (Sokalski Group CMU Materials Science and Engineering), Zeeshan Ahmad (Viswanathan Group, CMU Mechanical Engineering) won the poster awards ($1,000 travel award plus Echo Dot).

Megan Kirkendall Briggeman (Levy Lab, Pitt Physics), Amy Carlson (Evanseck Group, Duquesne Chemistry and Biochemistry), David Myers (Snoke Group, Pitt Physics) won the veteran awards (choice of Amazon Echo Spot/Echo or Google Home mini).

PQI undergraduate students Jessica Montone (Levy Lab) and Joe Albro (Levy Lab) presented a poster at the undergraduate session of Science2017.

Also, special thanks to the poster judges for participating in this event. 


NASA Workshop on Quantum Computing for Aeroscience and Engineering

  • By Leena Aggarwal
  • 15 November 2017

November 7-8, 2017, physics students and scientist from diffrent places were arrived at the NASA Langley research center for attending Quantum Computing workshop.

The objective of this workshop was to bring together experts on quantum information science and computation to understand the latest developments and current challenges in algorithms, hardware, and technology transition to engineering applications. The aims of workshop was to accelerate technology transition towards outstanding engineering problems that were expected to be achievable using quantum computations in the coming decade. The workshop’s goals were included developing a roadmap for success towards solution strategies for engineering applications. The interested stakeholders were presented or taken part in discussion on challenges to transition the current state-of-the-art to large scale engineering and data science related problems. 

 

Discussions were focused on the following four areas:

  • Quantum algorithms
  • Quantum computing hardware
  • Manufacturing and control of quantum systems
  • Engineering applications


American Leadership in Quantum Technology

  • By Burcu Ozden
  • 10 November 2017

On October 24, 2017 house committee on science, space, and technology held hearings on “American Leadership in Quantum Technology QT.” The goal of the hearing was to provide audiences the view of United States’ (US) and other nations’ research and development efforts to develop quantum computing and related technologies, and to identify what more can be done to robust these efforts. For this regard, committee members made their opening statements on quantum technology and US leadership in this area.  Witnesses from National Institute of Standards and Technology (NIST), National Science Foundation (NSF), Department of Energy (DOE), IBM, National Photonic Initiative, and Argon National Lab were emphasized the importance of study and research in quantum information science and technology to sustain the leadership in this area.


The Ability to Electrically Tune the Dimensionality of mesoscopic LAO/STO Channels

  • By Burcu Ozden
  • 27 October 2017

In this work, authors used conductive atomic force microscope (c-AFM) lithography in which the conduction is controlled by surface protons that are distributed on the LAO surface. They have created two conducting channel with varying witdhs as 10 and 200nm on a  LAO/STO heterostructures grown by pulsed-laser deposition. They designed the the devices in a way that two conducting channels connected in series with two leads and voltage probes. By using silver epoxy on the bottom of the STO substrate they created contacts for a back gate voltage. They investigated changes in the magnetotransport properties on the channels with different widths by varying back gate voltage and applied magnetic field. They measured the conductance for both narrow and wide channels and demonstarted the hysteresis of both channels with back gating. Saturation of the conductance at higher gate voltages was also shown. They were able to demonstrate dimensional crossover from 2d to 1D behavior with their magnetoconductance measurements.




Quantum materials: Where many paths meet

  • By Leena Aggarwal
  • 27 October 2017

In Nature, there exist materials with exotic properties that cannot be understood in the framework of classical theories. Such properties, however, are beautifully described by more sophisticated theoretical tools involving quantum mechanics.  Such materials are now known as the “quantum materials”. The range of exotic properties exhibited by the quantum materials is extremely broad and includes superconductivity, superfluidity, ferromagnetism, quantum hall effect, spin-liquidity, topological insulation, to name a few.

Superconductors, discovered by Kammerlingh Onnes, 1911, were first to emerge as quantum materials. In normal metals, the resistance arises due to inelastic scattering between the charge carriers (electrons) and defects in the periodic crystal lattice. The defects or scattering centres can be any distortion to the periodicity of the lattice like those due to presence of impurity or the thermal vibration of the lattice points. In superconductors, surprisingly, the resistance becomes zero despite the presence of a large number of impurities and at high temperatures where the lattice points can undergo vigorous thermal vibration. The question that how the charge carriers remained insensitive to such strong scattering centres could not be answered within any classical picture. A microscopic understanding of superconductivity was first provided by Bardeen, Cooper and Schrieffer (BCS) in 1951, only after substantial development of quantum mechanics and quantum field theories – the theories where quantum mechanics is combined with Einstein’s theory of relativity.


New Technique for Measuring the Layer-Resolved Charge Density

  • By Burcu Ozden
  • 25 October 2017

Recently Benjamin M. Hunt and his colleagues developed a new technique for measuring the layer-resolved charge density, from which they can map layer polarization of the valley or spin quantum numbers in bilayer graphine and other two dimensional materials. In this study, they demonstrated direct measurement of valley and orbital levels in bilayer graphite. They have detected that the four valley and orbital components have different weights on the two layers of the bilayer. By using Hunt’s technique one can probe layer, valley, and spin polarization quantitatively in other atomic layered materials, including twisted bilayer graphene and both homobilayer and heterobilayer of transition metal dichalcogenide

 


The new era of Polariton condensates

  • By Leena Aggarwal
  • 17 October 2017

In a recently published paper in Physics Today, David Snoke, a professor of physics and astronomy at the University of Pittsburgh and Jonathan Keeling who is a reader in theoretical condensed-matter physics at the University of St. Andrews in Scotland, have shown the superfluidity of light where photon treats as a gas of interacting bosonic atoms. They have demonstrated that how to engineer a Bose–Einstein condensation from light.

 


W. Vincent Liu Named a 2017 Fellow of the American Physical Society (APS)

  • By Leena Aggarwal
  • 16 October 2017

Congratulations to W. Vincent Liu for being named a 2017 Fellow of the American Physical Society (APS) by the Division of Atomic, Molecular & Optical Physics.

Vincent was elected for elucidating Landau damping of collective excitations in Bose-Einstein condensates, advancing the study of spin-polarized Fermi gases by introducing the concept of breached pair superfluidity, pioneering the theory of higher orbital bands in optical lattices, and working with experimentalists to confirm the theory.

 


Assistant Professor Tevis Jacobs Receives $305,000 from the National Science Foundation

  • By Leena Aggarwal
  • 16 October 2017

Tevis Jacobs,assistant professor of mechanical engineering and material science at the University of Pittsburgh's Swanson School of Engineering, received a grant from the National Science Foundation (NSF) to observe and measure nanoscale contact inside of an electron microscope-enabling for the first time visualization of the atomic structure of the component materials while they are in contact. The team's project will measure surface roughness of tiny particles and characterize the fundamental relationship between adhesion and roughness at small sizes.

Pages