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Search Publications by: Son T. Le (Assoc)

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Displaying 1 - 19 of 19

Are 2D Interfaces Really Flat?

March 15, 2022
Author(s)
Zhihui Cheng, Huairuo Zhang, Son Le, Hattan Abuzaid, Guoqing Li, Yifei Yu, Albert Davydov, Linyou Cao, Aaron Franklin, Curt A. Richter
Two-dimensional (2D) materials are amenable to external mechanical deformation and thus forming bubbles and wrinkles. However, little is known about the dynamics of 2D interfaces, especially their flatness under different conditions. Here we use cross

Edge channels of broken-symmetry quantum Hall states in graphene visualized by atomic force microscopy

May 14, 2021
Author(s)
Joseph A. Stroscio, Sungmin Kim, Johannes Schwenk, Daniel T. Walkup, Yihang Zeng, Fereshte Ghahari, Son T. Le, Marlou R. Slot, Julian Berwanger, Steven R. Blankenship, Kenji Watanabe, Takashi Taniguchi, Franz Giessibl, Nikolai Zhitenev, Cory Dean
The quantum Hall (QH) effect, a topologically non-trivial quantum phase, expanded and brought into focus the concept of topological order in physics. The topologically protected quantum Hall edge states are of crucial importance to the QH effect but have

Substrate-mediated hyperbolic phonon polaritons in MoO3

February 15, 2021
Author(s)
Jeffrey Schwartz, Son T. Le, Sergiy Krylyuk, Curt A. Richter, Albert Davydov, Andrea Centrone
Hyperbolic phonon polaritons (HPhPs) are hybrid excitations of light and coherent charge oscillations that exist in strongly optically anisotropic, two-dimensional materials (e.g., MoO3). These polaritons propagate through the material's volume with long

High-Resolution Biochemical Activity Measurements with Commercial Transistors

September 1, 2020
Author(s)
Seulki Cho, Son T. Le, Curt A. Richter, Arvind Balijepalli
We demonstrate that single-gated, commercially-sourced, field-effect transistors (FETs) operated with a lock- in amplifier (LIA) under closed-loop control can achieve an average pH resolution of 9x10^-4. This performance represents an 8-fold improvement

Achieving meV tunneling resolution in an in-operando scanning tunneling microscopy, atomic force microscopy, and magnetotransport system for quantum materials research

July 6, 2020
Author(s)
Johannes Schwenk, Sungmin Kim, Julian Berwanger, Fereshte Ghahari Kermani, Daniel T. Walkup, Marlou R. Slot, Son T. Le, W. G. Cullen, Steven R. Blankenship, Sasa Vranjkovic, Hans Hug, Young Kuk, Franz Giessibl, Joseph A. Stroscio
Research in new quantum materials require multi-mode measurements spanning length scales, correlations of atomic scale variables with macroscopic function, and with an ultimate energy resolution only obtainable at ultra-low temperatures, typically in a

Rapid, quantitative therapeutic screening for Alzheimer's enzymes enabled by optimal signal transduction with transistors

April 14, 2020
Author(s)
Son T. Le, Michelle A. Morris, Antonio Cardone, Nicholas B. Guros, Jeffery B. Klauda, Brent A. Sperling, Curt A. Richter, Harish C. Pant, Arvind Balijepalli
We show that commercially sourced n-channel silicon field-effect transistors (nFETs) operating under closed-loop control achieve a resolution of (7.2+/-0.3)x10-3 pH units with a bandwidth of 10 Hz. The results represent an 3-fold improvement in performance

QUANTUM-LIMITED 2D SENSORS FOR PH AND BIOSENSING

September 27, 2019
Author(s)
Arvind K. Balijepalli, Son T. Le, Harish C. Pant, Curt A. Richter
We have developed biosensors based on dual-gated field-effect transistors (FETs) that operate at the quantum capacitance limit. The FETs are fabricated with atomically thin MoS2 semiconducting films and top-gated with a room temperature ionic-liquid. The

Quantum Capacitance-Limited MoS2 Biosensors Enable Remote Label-Free Enzyme Measurements

August 7, 2019
Author(s)
Son T. Le, Nicholas B. Guros, Robert C. Bruce, Antonio Cardone, Niranjana D. Amin, Siyuan Zhang, Jeffery B. Klauda, Harish C. Pant, Curt A. Richter, Arvind Balijepalli
We have demonstrated atomically thin, quantum capacitance-limited, field-effect transistors (FETs) that enable the detection of pH changes with 75-fold higher sensitivity (4.4 V/pH) over the Nernst value of 59 mV/pH at room temperature when used as a

Reproducible Performance Improvements to Monolayer MoS2 Transistors through Exposed Material Forming Gas Annealing

April 16, 2019
Author(s)
Nicholas B. Guros, Son T. Le, Siyuan Zhang, Brent A. Sperling, Jeffery B. Klauda, Curt A. Richter, Arvind Balijepalli
We have developed an optimized process to realize high-performance field-effect transistor (FET) arrays from large-area 2D MoS2 films with an average yield of 85 %. A central element of the technique is a new exposed film forming gas anneal (EF- FGA) that

Contact and Non-Contact Measurement of Electronic Transport in Individual 2D SnS Colloidal Semiconductor Nanocrystals

September 24, 2018
Author(s)
Adam J. Biacchi, Son T. Le, Brian G. Alberding, Joseph A. Hagmann, Sujitra J. Pookpanratana, Edwin J. Heilweil, Curt A. Richter, Angela R. Hight Walker
Colloidal-based solution syntheses offer a scalable and cost-efficient means of producing 2D nanomaterials in high yield. While much progress has been made towards the controlled and tailorable synthesis of semiconductor nanocrystals in solution, it

Interacting nanoscale magnetic cluster arrays in molybdenum oxide bronzes

May 26, 2017
Author(s)
Joseph A. Hagmann, Son T. Le, Lynn F. Schneemeyer, Joseph A. Stroscio, Tiglet Besara, Theo Siegrist, Curt A. Richter, David G. Seiler
In this study, we examine several reduced ternary molybdates in the family of rare earth molybdenum bronzes produced by electrochemical synthesis with composition LnMo16O44. These compounds contain an array of electrically isolated but magnetically

Elucidating the Structural and Electronic Properties of Solution-Synthesized 2D SnS Crystals

March 28, 2017
Author(s)
Adam J. Biacchi, Brian G. Alberding, Son T. Le, Joseph A. Hagmann, Sugata Chowdhury, Curt A. Richter, Edwin J. Heilweil, Angela R. Hight Walker
The vast majority of nanoscale 2D materials are synthesized by exfoliation or gas phase deposition techniques. Alternatively, bottom-up colloidal solution syntheses offer a scalable and cost-efficient means of producing 2D nanomaterials in high yield

Edge-state Transport in Graphene p-n Junctions in the Quantum Hall Regime

December 7, 2015
Author(s)
Nikolai Klimov, Son T. Le, Jun Yan, Pratik Agnihotri, Everett Comfort, Ji Ung Lee, David B. Newell, Curt A. Richter
We experimentally investigate charge carrier transport in a graphene p-n junction device by using independent p-type and n-type electrostatic gating which allow full characterization of the junction interface in the quantum Hall regime covering a wide