Skip to main content


Broken symmetries and excitation spectra of interacting electrons in partially filled Landau levels

Cornell Affiliated Author(s)
Gelareh Farahi
Cheng-Li Chiu
Xiaomeng Liu
Zlatko Papic
Kenji Watanabe
Takashi Taniguchi
Michael Zaletel
Ali Yazdani

Interacting electrons in flat bands give rise to a variety of quantum phases. One fundamental aspect of such states is the ordering of the various flavours - such as spin or valley - that the electrons can undergo and the excitation spectrum of the broken symmetry states that they form. These properties cannot be probed directly with electrical transport measurements.

Nature Physics
Date Published
Group (Lab)
Xiaomeng Liu Group

Magnetotropic susceptibility

Cornell Affiliated Author(s)
A. Shekhter
R. McDonald
B. Ramshaw
K. Modic

The magnetotropic susceptibility is the thermodynamic coefficient associated with the rotational anisotropy of the free energy in an external magnetic field and is closely related to the magnetic susceptibility. It emerges naturally in frequency-shift measurements of oscillating mechanical cantilevers, which are becoming an increasingly important tool in the quantitative study of the thermodynamics of modern condensed-matter systems.

Physical Review B
Date Published
Group (Lab)
Brad Ramshaw Group

New perspectives on student reasoning about measurement uncertainty: More or better data

Cornell Affiliated Author(s)
Andy Schang
Matthew Dew
Emily Stump
N. Holmes
Gina Passante

Uncertainty is an important and fundamental concept in physics education. Students are often first exposed to uncertainty in introductory labs, expand their knowledge across lab courses, and then are introduced to quantum mechanical uncertainty in upper-division courses. This study is part of a larger project evaluating student thinking about uncertainty across these contexts.

Physical Review Physics Education Research
Date Published
Group (Lab)
Natasha Holmes Group

Detection of a pair density wave state in UTe2

Cornell Affiliated Author(s)
Q. Gu
J.P. Carroll
S. Wang
S. Ran
C. Broyles
H. Siddiquee
N.P. Butch
S.R. Saha
J. Paglione
J.C.S. Davis
X. Liu

Spin-triplet topological superconductors should exhibit many unprecedented electronic properties, including fractionalized electronic states relevant to quantum information processing. Although UTe2 may embody such bulk topological superconductivity1–11, its superconductive order parameter Δ(k) remains unknown12. Many diverse forms for Δ(k) are physically possible12 in such heavy fermion materials13.

Date Published
Group (Lab)
J.C. Seamus Davis Group

Non-Abelian braiding of graph vertices in a superconducting processor

Cornell Affiliated Author(s)
T.I. Andersen
Y.D. Lensky
K. Kechedzhi
I.K. Drozdov
A. Bengtsson
S. Hong
A. Morvan
X. Mi
A. Opremcak
R. Acharya
R. Allen
M. Ansmann
F. Arute
K. Arya
A. Asfaw
J. Atalaya
R. Babbush
D. Bacon
J.C. Bardin
G. Bortoli
A. Bourassa
J. Bovaird
L. Brill
M. Broughton
B.B. Buckley
D.A. Buell
T. Burger
B. Burkett
N. Bushnell
Z. Chen
B. Chiaro
D. Chik
C. Chou
J. Cogan
R. Collins
P. Conner
W. Courtney
A.L. Crook
B. Curtin
D.M. Debroy
Del Barba
S. Demura
A. Dunsworth
D. Eppens
C. Erickson
L. Faoro
E. Farhi
R. Fatemi
V.S. Ferreira
L.F. Burgos
E. Forati
A.G. Fowler
B. Foxen
W. Giang
C. Gidney
D. Gilboa
M. Giustina
R. Gosula
A.G. Dau
J.A. Gross
S. Habegger
M.C. Hamilton
M. Hansen
M.P. Harrigan
S.D. Harrington
P. Heu
J. Hilton
M.R. Hoffmann
T. Huang
A. Huff
W.J. Huggins
L.B. Ioffe
S.V. Isakov
J. Iveland
E. Jeffrey
Z. Jiang
C. Jones
P. Juhas
D. Kafri
T. Khattar
M. Khezri
M. Kieferová
S. Kim
A. Kitaev
P.V. Klimov
A.R. Klots
A.N. Korotkov
F. Kostritsa
J.M. Kreikebaum
D. Landhuis
P. Laptev
K.-M. Lau
L. Laws
J. Lee
K.W. Lee
B.J. Lester
A.T. Lill
W. Liu
A. Locharla
E. Lucero
F.D. Malone
O. Martin
J.R. McClean
T. McCourt
M. McEwen
K.C. Miao
A. Mieszala
M. Mohseni
S. Montazeri
E. Mount
R. Movassagh
W. Mruczkiewicz
O. Naaman
M. Neeley
C. Neill
A. Nersisyan
M. Newman
J.H. Ng
A. Nguyen
M. Nguyen
M.Y. Niu
T.E. O’Brien
S. Omonije
A. Petukhov
R. Potter
L.P. Pryadko
C. Quintana
C. Rocque
N.C. Rubin
N. Saei
D. Sank
K. Sankaragomathi
K.J. Satzinger
H.F. Schurkus
C. Schuster
M.J. Shearn
A. Shorter
N. Shutty
V. Shvarts
J. Skruzny
W.C. Smith
R. Somma
G. Sterling
D. Strain
M. Szalay
A. Torres
G. Vidal
B. Villalonga
C.V. Heidweiller
T. White
B.W.K. Woo
C. Xing
Z.J. Yao
P. Yeh
J. Yoo
G. Young
A. Zalcman
Y. Zhang
N. Zhu
N. Zobrist
H. Neven
S. Boixo
A. Megrant
J. Kelly
Y. Chen
V. Smelyanskiy
E.-A. Kim
I. Aleiner
P. Roushan
Google Collaborators

Indistinguishability of particles is a fundamental principle of quantum mechanics1. For all elementary and quasiparticles observed to date—including fermions, bosons and Abelian anyons—this principle guarantees that the braiding of identical particles leaves the system unchanged2,3. However, in two spatial dimensions, an intriguing possibility exists: braiding of non-Abelian anyons causes rotations in a space of topologically degenerate wavefunctions4–8. Hence, it can change the observables of the system without violating the principle of indistinguishability.

Date Published
Group (Lab)

Strain stiffening elastomers with swelling inclusions

Cornell Affiliated Author(s)
S. Heyden
R.W. Style
E.R. Dufresne

Inhomogeneously swollen elastomers are an emergent class of materials, comprising elastic matrices with inclusion phases in the form of microgel particles or osmolytes. Inclusion phases can undergo osmotically driven swelling and deswelling over orders of magnitude. In the swollen state, the inclusions typically have negligible Young's modulus, and the matrix is strongly deformed. In that regime, the effective mechanical properties of the composite are governed by the matrix.

Soft Matter
Date Published
Group (Lab)
Eric Dufresne Group

Quantum Oscillations in Graphene Using Surface Acoustic Wave Resonators

Cornell Affiliated Author(s)
Yawen Fang
Yang Xu
Kaifei Kang
Benyamin Davaji
Kenji Watanabe
Takashi Taniguchi
Amit Lal
Kin Mak
Jie Shan
B. Ramshaw

Surface acoustic waves (SAWs) provide a contactless method for measuring wave-vector-dependent conductivity. This technique has been used to discover emergent length scales in the fractional quantum Hall regime of traditional, semiconductor-based heterostructures. SAWs would appear to be an ideal match for van der Waals heterostructures, but the right combination of substrate and experimental geometry to allow access to the quantum transport regime has not yet been found.

Physical Review Letters
Date Published
Group (Lab)
Brad Ramshaw Group