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Search Publications by: Yanfei Yang (Fed)

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Displaying 1 - 25 of 30

Graphene-Based Star-Mesh Resistance Networks

July 12, 2023
Dean G. Jarrett, Ching-Chen Yeh, Shamith Payagala, Alireza Panna, Yanfei Yang, Linli Meng, Swapnil Mhatre, Ngoc Thanh Mai Tran, Heather Hill, Dipanjan Saha, Randolph Elmquist, David B. Newell, Albert Rigosi

A self-assembled graphene ribbon grown on SiC

January 2, 2020
Bi Y. Wu, Yanfei Yang, Albert Rigosi, Jiuning Hu, Hsin Y. Lee, Guangjun Cheng, Vishal Panchal, Mattias Kruskopf, Hanbyul Jin, Kenji Watanabe, Takashi Taniguchi, David B. Newell, Randolph Elmquist, Chi-Te Liang

Characterization of graphene conductance using a microwave cavity

January 9, 2019
Jan Obrzut, Keith White, Yanfei Yang, Randolph Elmquist
Surface conductance of graphene films is investigated in a non-contact microwave cavity operating at 7.4543 GHz. This cavity technique characterizes specimens with high accuracy, without disruption of morphological integrity and without the processing

Utilizing confocal laser scanning microscopy for rapid optical characterization of graphene

November 20, 2018
Vishal Panchal, Yanfei Yang, Guangjun Cheng, Jiuning Hu, Mattias Kruskopf, Chieh-I Liu, Albert Rigosi, Christos Melios, Angela R. Hight Walker, David B. Newell, Olga Kazakova, Randolph Elmquist
Confocal laser scanning microscopy (CLSM) is a non-destructive, highly-efficient optical characterization method for large-area analysis of graphene on different substrates, which can be applied in ambient air, does not require additional sample

Part-per-million quantization and current-induced breakdown of the quantum anomalous Hall effect

August 27, 2018
Eli J. Fox, Ilan T. Rosen, Yanfei Yang, George R. Jones Jr., Randolph Elmquist, Xufeng Kou, Lei Pan, Kang L. Wang, D. Goldhaber-Gordon
In the quantum anomalous Hall effect, quantized Hall resistance and vanishing longitudinal resistivity are predicted to result from the presence of dissipationless, chiral edge states and an insulating two-dimensional bulk, without requiring an external

Quantum transport in graphene p-n junctions with Moire superlattice modulation

July 12, 2018
Jiuning Hu, Albert Rigosi, Ji Ung Lee, Hsin Y. Lee, Yanfei Yang, Chieh-I Liu, Randolph Elmquist, David B. Newell
This work presents simulations of quantum transport in graphene p-n junctions (pnJs) in which Moire superlattice potentials are incorporated to demonstrate the interplay of the effect of pnJs and Moire superlattice potentials. It is shown that the

Epitaxial Graphene for High-Current QHE Resistance Standards

July 9, 2018
Mattias Kruskopf, Jiuning Hu, Bi Y. Wu, Yanfei Yang, Hsin Y. Lee, Albert F. Rigosi, David B. Newell, Randolph E. Elmquist
We report the growth of large-area monolayer graphene on the centimeter scale using an optimized growth process allowing for reproducibility and morphology improvements. Magneto-transport measurements on graphene quantum Hall effect devices demonstrate the

Epitaxial Graphene p-n Junctions

July 9, 2018
Jiuning Hu, Mattias Kruskopf, Yanfei Yang, Bi Y. Wu, Jifa Tian, Alireza R. Panna, Albert F. Rigosi, Hsin Y. Lee, George R. Jones Jr., Marlin E. Kraft, Dean G. Jarrett, Kenji Watanabe, Takashi Taniguchi, Randolph E. Elmquist, David B. Newell
We report the fabrication and measurement of top gated epitaxial graphene p-n junctions where exfoliated hexgonal boron nitride (hBN) is used as the gate dielectric. The four terminal longitudinal resistance across a single junction is well quantized at R_

Transport of NIST Graphene Quantized Hall Devices and Comparison with AIST Gallium-Arsenide Quantized Hall Devices

July 9, 2018
Dean G. Jarrett, Takehiko Oe, Randolph E. Elmquist, Nobu Kaneko, Albert F. Rigosi, Bi Y. Wu, Hsin Y. Lee, Yanfei Yang
We report the results of a pilot study where two graphene quantized Hall resistance (QHR) devices made at the National Institute of Standards and Technology (NIST) were hand carried from the USA to the National Institute for Advanced Industrial Science and

A Table-Top Graphene Quantized Hall Standard

July 8, 2018
Albert F. Rigosi, Alireza R. Panna, Shamith U. Payagala, George R. Jones Jr., Marlin E. Kraft, Mattias Kruskopf, Bi Y. Wu, Hsin Y. Lee, Yanfei Yang, Dean G. Jarrett, Randolph E. Elmquist, David B. Newell
We report the performance of a quantum standard based on epitaxial graphene maintained in a 5 T table-top cryocooler system. The ν = 2 resistance plateau, with a value of RK-90/2, is used to scale to 1 kΩ, allowing comparisons of the performance of a

Examining epitaxial graphene surface conductivity and quantum Hall device stability with Parylene passivation

March 20, 2018
Albert F. Rigosi, Chieh-I Liu, Bi Y. Wu, Hsin Y. Lee, Mattias Kruskopf, Yanfei Yang, Heather M. Hill, Jiuning Hu, Emily G. Bittle, Jan Obrzut, Angela R. Hight Walker, Randolph E. Elmquist, David B. Newell
When it comes to the advancement of quantized Hall resistance (QHR) standards, homogeneous, single-crystal, monolayer epitaxial graphene (EG) is the most promising candidate. EG-based quantum Hall devices, though emerging as a useful tool for metrology

Measuring the dielectric and optical response of millimeter-scale amorphous and hexagonal boron nitride films grown on epitaxial graphene

December 1, 2017
Albert F. Rigosi, Heather M. Hill, Nicholas R. Glavin, Sujitra J. Pookpanratana, Yanfei Yang, Alexander G. Boosalis, Jiuning Hu, Anthony Rice, Andrew A. Allerman, Nhan V. Nguyen, Christina A. Hacker, Randolph E. Elmquist, Angela R. Hight Walker, David B. Newell
Monolayer epitaxial graphene (EG), grown on the Si face of SiC, is an advantageous material for a variety of electronic and optical applications. EG forms as a single crystal over millimeter- scale areas and consequently, the large scale single crystal can

Probing the dielectric response of the interfacial buffer layer in epitaxial graphene via optical spectroscopy

November 28, 2017
Heather M. Hill, Albert Rigosi, Sugata Chowdhury, Yanfei Yang, Nhan Van Nguyen, Francesca Tavazza, Randolph Elmquist, David B. Newell, Angela R. Hight Walker
Monolayer epitaxial graphene (EG) is a suitable candidate for a variety of electronic applications. One advantage of EG growth on the Si face of SiC is that it develops as a single crystal, as does the layer below, referred to as the interfacial buffer

Electrical stabilization of surface resistivity in epitaxial graphene systems by amorphous boron nitride encapsulation

May 25, 2017
Albert F. Rigosi, Chieh-I Liu, Nicholas R. Glavin, Yanfei Yang, Heather M. Hill, Jiuning Hu, Angela R. Hight Walker, Curt A. Richter, Randolph E. Elmquist, David B. Newell
Homogeneous monolayer epitaxial graphene (EG) is an ideal candidate for the development of millimeter-sized devices with single-crystal domains. A clean fabrication process was used to produce EG-based devices with n-type doping level of order 10^12 cm^-2

Preservation of surface conductivity and dielectric loss tangent in large-scale, encapsulated epitaxial graphene measured by non-contact microwave cavity perturbations

May 19, 2017
Albert F. Rigosi, Nicholas R. Glavin, Chieh-I Liu, Yanfei Yang, Jan Obrzut, Heather M. Hill, Jiuning Hu, Hsin Y. Lee, Angela R. Hight Walker, Curt A. Richter, Randolph E. Elmquist, David B. Newell
Regarding the improvement of current quantized Hall resistance (QHR) standards, one promising avenue is the growth of homogeneous monolayer epitaxial graphene (EG). A clean and simple process was used to produce large, precise areas of EG. Properties like

Epitaxial graphene homogeneity and quantum Hall effect in millimeter-scale devices

April 1, 2017
Yanfei Yang, Guangjun Cheng, Chiashain Chuang, Angela R. Hight Walker, Randolph E. Elmquist, Irene G. Calizo, Randall M. Feenstra, Patrick Mende
Quantized magnetotransport is observed in 5.6 × 5.6 mm2 epitaxial graphene devices, grown using highly constrained sublimation on the Si-face of SiC(0001) at high temperature (1900 °C). The precise quantized Hall resistance of Rxy = h/〖2e〗^2 is maintained

Temperature dependence of electron density and electron-electron interactions in monolayer epitaxial graphene grown on SiC

January 25, 2017
Chieh W. Liu, Chiashain Chuang, Yanfei Yang, Randolph Elmquist, Yi-Ju Ho, Hsin Y. Lee, Chi-Te Liang
We report carrier density measurements and electron-electron (e-e) interactions in monolayer epitaxial graphene grown on SiC. The temperature (T)-independent carrier density determined from the Shubnikov-de Haas (SdH) oscillations clearly demonstrates that

Insulator-quantum Hall transition in monolayer epitaxial graphene

July 22, 2016
Lung-I Huang, Yanfei Yang, Randolph Elmquist, Shun-Tsung Lo, Fan-Hung H. Liu, Chi-Te Laing
We report on magneto-transport measurements on low-density, large-area monolayer epitaxial graphene devices grown on SiC. We observe temperature (T)-independent crossing points in the longitudinal resistivity (rho)sub(xx), which are signatures of the

Surface conductance of graphene from non-contact resonant cavity

March 15, 2016
Jan Obrzut, Caglar Dogu Emiroglu, Oleg A. Kirillov, Yanfei Yang, Randolph E. Elmquist
A method is established to reliably determine surface conductance of single-layer or multi-layer atomically thin nano-carbon graphene structures. These can be synthesized by chemical vapor deposition (CVD), epitaxial growth on silicon carbide (SiC)