4.9k citations · 9.6k across the 35 of their papers we have counts for
30 papers · 1 filter
Time, momentum, and energy resolved pump-probe tunneling spectroscopy of two-dimensional electron systems
H. M. Yoo, M. Korkusinski, D. Miravet +5
Real-time probing of electrons can uncover intricate relaxation mechanisms and many-body interactions hidden in strongly correlated materials. While experimenters have used ultrafa…
Superconductivity and strong interactions in a tunable moiré quasiperiodic crystal
Aviram Uri, Sergio C. de la Barrera, Mallika T. Randeria +10
Electronic states in quasiperiodic crystals generally preclude a Bloch description, rendering them simultaneously fascinating and enigmatic. Owing to their complexity and relative…
Cascade of isospin phase transitions in Bernal bilayer graphene at zero magnetic field
Sergio C. de la Barrera, Samuel Aronson, Zhiren Zheng +5
Emergent phenomena arising from the collective behavior of electrons is generally expected when Coulomb interactions dominate over the kinetic energy, as in delocalized quasipartic…
Strong interlayer charge transfer due to exciton condensation in an electrically-isolated GaAs quantum well bilayer
Joonho Jang, Heun Mo Yoo, Loren N. Pfeiffer +3
We introduce a design of electrically isolated floating bilayer GaAs quantum wells (QW) in which application of a large gating voltage controllably and highly reproducibly induces…
Correlated double-electron additions at the edge of a two-dimensional electronic system
Ahmet Demir, Neal Staley, Samuel Aronson +5
We create laterally large and low disorder quantum well based quantum dots to study single electron additions to two dimensional electron systems (2DES). Electrons tunnel into thes…
Complete spin phase diagram of the fractional quantum Hall liquid
H. M. Yoo, K. W. Baldwin, K. West +2
Study of the ground-state electronic spin-polarization can permit discovery and identification of novel correlated phases in the quantum Hall (QH) system. It can thus determine the…
Electronic Compressibility of Magic-Angle Graphene Superlattices
S. L. Tomarken, Y. Cao, A. Demir +4
We report the first electronic compressibility measurements of magic-angle twisted bilayer graphene. The evolution of the compressibility with carrier density offers insights into…
Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
Yuan Cao, Valla Fatemi, Ahmet Demir +9
Van der Waals (vdW) heterostructures are an emergent class of metamaterials comprised of vertically stacked two-dimensional (2D) building blocks, which provide us with a vast tool…
Full Momentum and Energy Resolved Spectral Function of a 2D Electronic System
Joonho Jang, Heun Mo Yoo, Loren Pfeiffer +3
The single-particle spectral function measures the density of electronic states (DOS) in a material as a function of both momentum and energy, providing central insights into pheno…
Direct measurement of discrete valley and orbital quantum numbers in a multicomponent quantum Hall system
B. M. Hunt, J. I. A. Li, A. A. Zibrov +8
Strongly interacting two dimensional electron systems (2DESs) host a complex landscape of broken symmetry states. The possible ground states are further expanded by internal degree…
Observation of Helical Edge States and Fractional Quantum Hall Effect in a Graphene Electron-hole Bilayer
J. D. Sanchez-Yamagishi, J. Y. Luo, A. F. Young +5
A quantum Hall edge state provides a rich foundation to study electrons in 1-dimension (1d) but is limited to chiral propagation along a single direction. Here, we demonstrate a ve…
Electrostatic Coupling between Two Surfaces of a Topological Insulator Nanodevice
Valla Fatemi, Benjamin Hunt, Hadar Steinberg +8
We report on electronic transport measurements of dual-gated nano-devices of the low-carrier density topological insulator Bi1.5Sb0.5Te1.7Se1.3. In all devices the upper and lower…
Tunable symmetry breaking and helical edge transport in a graphene quantum spin Hall state
A. F. Young, J. D. Sanchez-Yamagishi, B. Hunt +5
Low-dimensional electronic systems have traditionally been obtained by electrostatically confining electrons, either in heterostructures or in intrinsically nanoscale materials suc…
Massive Dirac fermions and Hofstadter butterfly in a van der Waals heterostructure
B. Hunt, J. D. Sanchez-Yamagishi, A. F. Young +6
Van der Waals heterostructures comprise a new class of artificial materials formed by stacking atomically-thin planar crystals. Here, we demonstrate band structure engineering of a…
Observations of Plasmarons in a System of Massive Electrons
O. E. Dial, R. C. Ashoori, L. N. Pfeiffer +1
Calculations of the single particle density of states (SPDOS) of electron liquids have long predicted that there exist two distinct charged excitations: the usual quasiparticle con…
Large capacitance enhancement and negative compressibility of two-dimensional electronic systems at LaAlO/SrTiO interfaces
Lu Li, C. Richter, S. Paetel +3
Novel electronic systems forming at oxide interfaces comprise a class of new materials with a wide array of potential applications. A high mobility electron system forms at the LaA…
Anomalous structure in the single particle spectrum of the fractional quantum Hall effect
O. E. Dial, R. C. Ashoori, L. N. Pfeiffer +1
The two-dimensional electron system (2DES) is a unique laboratory for the physics of interacting particles. Application of a large magnetic field produces massively degenerate quan…
High Resolution Spectroscopy of Two-Dimensional Electron Systems
O. E. Dial, R. C. Ashoori, L. N. Pfeiffer +1
Spectroscopic methods involving the sudden injection or ejection of electrons in materials are a powerful probe of electronic structure and interactions. These techniques, such as…
The Density of States in the Two-Dimensional Electron Gas and Quantum Dots (Ph.D. thesis, Cornell University, January 1991)
R. C. Ashoori
This thesis describes capacitance and tunneling experiments performed on two-dimensional electron gas (2DEG) and quantum dot systems. It develops a system of equations that allow d…
Imaging Transport Resonances in the Quantum Hall Effect
G. A. Steele, R. C. Ashoori, L. N. Pfeiffer +1
We use a scanning capacitance probe to image transport in the quantum Hall system. Applying a DC bias voltage to the tip induces a ring-shaped incompressible strip (IS) in the 2D e…
Direct observation of the charging of a 2D electron gas through an incompressible strip in the quantum Hall regime
P. I. Glicofridis, G. Finkelstein, R. C. Ashoori +1
Using charge accumulation imaging, we measure the charge flow across an incompressible strip and follow its evolution with magnetic field. The strip runs parallel to the edge of a…
Topographic Mapping of the Quantum Hall Liquid using a Few-Electron Bubble
G. Finkelstein, P. I. Glicofridis, R. C. Ashoori +1
A scanning probe technique was used to obtain a high-resolution map of the random electrostatic potential inside the quantum Hall liquid. A sharp metal tip, scanned above a semicon…
Localization in Artificial Disorder - Two Coupled Quantum Dots
M. Brodsky, N. B. Zhitenev, R. C. Ashoori +2
Using Single Electron Capacitance Spectroscopy, we study electron additions in quantum dots containing two potential minima separated by a shallow barrier. Analysis of addition spe…
The Localization-Delocalization Transition in Quantum Dots
N. B. Zhitenev, M. Brodsky, R. C. Ashoori +2
Single-electron capacitance spectroscopy precisely measures the energies required to add individual electrons to a quantum dot. The spatial extent of electronic wavefunctions is pr…