1181-B 10 JUNE 2022 • VOL 376 ISSUE 6598 science.org SCIENCE
RESEARCH
QUANTUM COMPUTING
Learning from quantum
experiments
There is considerable interest in
extending the recent success of
quantum computers in out-
performing their conventional
classical counterparts (quantum
advantage) from some model
mathematical problems to more
meaningful tasks. Huang et al.
show how manipulating multiple
quantum states can provide
an exponential advantage over
classical processing of measure-
ments of single-quantum states
for certain learning tasks. These
include predicting properties of
physical systems, performing
quantum principal component
analysis on noisy states, and
learning approximate models
of physical dynamics (see the
Perspective by Dunjko). In
their proof-of-principle experi-
ments using up to 40 qubits on
a Google Sycamore quantum
processor, the authors achieved
almost four orders of magnitude
of reduction in the required
number of experiments over
the best-known classical lower
bounds. —YS
Science, abn7293, this issue p. 1182;
see also abp9885, p. 1154
QUANTUM SIMULATION
Solving hard graph
problems
Realizing quantum speedup for
solving practical, computation-
ally hard problems is the central
challenge in quantum informa-
tion science. Ebadi et al. used
Rydberg atom arrays composed
of up to 289 coupled qubits
in two spatial dimensions to
investigate quantum optimiza-
tion algorithms for solving the
maximum independent set, a
paradigmatic nondeterministic
polynomial time–hard combina-
torial optimization problem (see
the Perspective by Schleier-
Smith). A hardware-efficient
encoding protocol associated
with Rydberg blockade was
used to realize a closed-loop
optimization method to test
several variational algorithms
and subsequently apply them to
systematically explore a class of
nonplanar graphs with program-
mable connectivity. The results
demonstrate the potential of
quantum machines as a tool for
the discovery of new promising
algorithm classes. —ISO
Science, abo6587, this issue p. 1209;
see also abq3754, p. 1155PHOSPHORUS CHEMISTRY
Chiral-at-P products via
H-bond catalysis
Hydrogen (H)–bonding catalysis
has recently proven useful for
activating carbon-chlorine bonds
to form just one of two possible
mirror-image products. Forbes
and Jacobsen now extend this
approach to desymmetriza-
tion of phosphorus(V) [P(V)]
dichloride compounds (see
the Perspective by Verdaguer).
Using chiral urea catalysts, the
authors could displace just one
of two chlorides with an amine,
thereby producing a versatile
P(V) intermediate. Subsequent
selective displacement of the
remaining chloride and/or amine
offers access to a wide range of
chiral-at-P compounds, a class
of increasing pharmaceutical
interest. —JSY
Science, abp8488, this issue p. 1230;
see also abq5073, p. 1157PROTEIN BIOPHYSICS
Stabilizing receptors with
cholesterol
Membrane-embedded G pro-
tein–coupled receptors such
as the b 2 -adrenergic receptor
(b 2 AR) mingle with cholesterol,
which modulates their assembly
and stability. Serdiuk et al. exam-
ined the effects of a cholesterol
analog on the mechanical and
energetic properties of the b 2 AR
at different temperatures. The
authors showed that whereas
the presence of the cholesterolanalog in liposomes had minimal
effects at 25∞ and 42∞C, it stabi-
lized subsets of conformations
of the b 2 AR that were important
for basal activity at 37∞C. —JFF
Sci. Signal. 15 , eabi7031 (2022).CANCER IMMUNOLOGY
ILC2s help tumors
Group 2 innate lymphoid cells
(ILC2s) protect against parasitic
infections and are implicated
in allergies, yet their role in
antitumor immunity remains
unclear. Jou et al. used vari-
ous genetic mouse models to
study the roles of ILC2s in
colorectal cancer (CRC). They
found that ILC2s were linked to
an immunosuppressive tumor
microenvironment, where dele-
tion of these cells led to less CRC
tumor burd en. ILC2s specifically
responded to high interleu-
kin-25 (IL-25) expression in CRC
tumors, and in turn inducing
immunosuppressive myeloid-
derived suppressor cells.
Therapeutically blocking the
IL-25 receptor on ILC2s lowered
tumor burden and led to more
favorable antitumor immune
responses. —DAE
Sci. Immunol. 7 , eabn0175 (2022).Edited by Michael FunkALSO IN SCIENCE JOURNALS