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BEGIN:VEVENT
SUMMARY:Harpreet Arora (Caltech)
DTSTART;VALUE=DATE-TIME:20200529T180000Z
DTEND;VALUE=DATE-TIME:20200529T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/1
DESCRIPTION:Title: Investigating superconductivity in Twisted Bilayer Graphene (TBG)
\nby Harpreet Arora (Caltech) as part of IQIM Seminar Series\n\n\nAbstract
\nWhile graphene has been dubbed as a ‘wonder material' because of amazi
ng characteristics such as the ability to conduct electricity better than
copper and being two hundred times stronger than steel\, until recently\,
the key quantum phenomenon of superconductivity was missing from the list
of properties exhibited by graphene. In 2018\, an astonishing discovery sh
owed that by placing two sheets of graphene on top of each other which are
rotationally misaligned by a small angle - in a structure known as Twiste
d Bilayer Graphene (TBG)\, it is possible to realize superconductivity whe
n the rotation angle is close to the ‘Magic Angle' value of 1.1 degrees$
^{[1]}$. More surprisingly\, superconductivity in the initial reports was
observed in close proximity to insulating states - resembling the phase di
agram of High Tc superconductors. This sparked a fierce debate about its o
rigin and its possible relation to High Tc superconductors. In this talk\,
I will show that by carefully engineering the dielectric environment of T
BG\, it is possible to stabilize superconductivity in non-magic angle TBG
devices without the presence of any insulating states$^{[2]}$. This discov
ery imposes severe constraints on the origin of superconductivity in TBG.
I will also discuss measurements providing direct evidence of spin-orbit c
oupling induced in TBG for the first time. I will conclude by talking abou
t possible experiments that will shed more light on the nature of supercon
ductivity in TBG.\n\n\n[1] Cao et al. "Unconventional superconductivity in
magic-angle graphene superlattices." Nature 556\, 43–50 (2018).\n\n \n[
2] Arora et al. "Superconductivity in metallic twisted bilayer graphene st
abilized by WSe2" Nature (2020) In press. Preprint available at https://ar
xiv.org/abs/2002.03003\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eugene Tang (Caltech)
DTSTART;VALUE=DATE-TIME:20200605T180000Z
DTEND;VALUE=DATE-TIME:20200605T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/2
DESCRIPTION:Title: The ghost in the radiation: Robust encodings of the black hole interi
or\nby Eugene Tang (Caltech) as part of IQIM Seminar Series\n\n\nAbstr
act\nWe reconsider the black hole firewall puzzle\, emphasizing that quant
um error-correction\, computational complexity\, and pseudorandomness are
crucial concepts for understanding the black hole interior. We assume that
the Hawking radiation emitted by an old black hole is pseudorandom\, mean
ing that it cannot be distinguished from a perfectly thermal state by any
efficient quantum computation acting on the radiation alone. We then infer
the existence of a subspace of the radiation system which we interpret as
an encoding of the black hole interior. This encoded interior is entangle
d with the late outgoing Hawking quanta emitted by the old black hole\, an
d is inaccessible to computationally bounded observers who are outside the
black hole. Specifically\, efficient operations acting on the radiation\,
those with quantum computational complexity polynomial in the entropy of
the remaining black hole\, commute with a complete set of logical operator
s acting on the encoded interior\, up to corrections which are exponential
ly small in the entropy. Thus\, under our pseudorandomness assumption\, th
e black hole interior is well protected from exterior observers as long as
the remaining black hole is macroscopic.\n\nThe talk will be an introduct
ory version of my joint work with Isaac Kim and John Preskill\, available
at arxiv:2003.05451.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christina Knapp (Caltech)
DTSTART;VALUE=DATE-TIME:20200619T180000Z
DTEND;VALUE=DATE-TIME:20200619T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/4
DESCRIPTION:Title: Time-reversal-invariant topological superconductors and the fractiona
l Josephson effect\nby Christina Knapp (Caltech) as part of IQIM Semin
ar Series\n\n\nAbstract\nTime-reversal-invariant topological superconducto
r (TRITOPS) wires host Majorana-zero-mode Kramers pairs that have been pre
dicted to mediate a fractional Josephson effect. We explore the fate of t
he TRITOPS fractional Josephson effect in the presence of local time-depen
dent perturbations that instantaneously preserve time-reversal symmetry.
This talk will review why Majorana zero modes have attracted intense inter
est in both the condensed matter and quantum computing communities. We wi
ll then focus on the Majorana-zero-mode Kramers pairs appearing in TRITOPS
wires. We consider a Josephson junction between two TRITOPS wires and de
monstrate that the existence of a symmetry-protected ground state degenera
cy does not result in a robust adiabatic cycle.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sepehr Ghazi Nezami (Caltech)
DTSTART;VALUE=DATE-TIME:20200409T190000Z
DTEND;VALUE=DATE-TIME:20200409T200000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/5
DESCRIPTION:Title: Teleportation by size\, traversable wormholes\, and quantum gravity i
n the lab\nby Sepehr Ghazi Nezami (Caltech) as part of IQIM Seminar Se
ries\n\n\nAbstract\nWith the long-term goal of studying quantum gravity in
the lab\, we propose holographic teleportation protocols that can be read
ily executed in table-top experiments. These protocols exhibit similar beh
avior to that seen in recent traversable wormhole constructions: informati
on that is scrambled into one half of an entangled system will\, following
a weak coupling between the two halves\, unscramble into the other half.
We introduce the concept of "teleportation by size" to capture how the phy
sics of operator-size growth naturally leads to information transmission.
The transmission of a signal through a semi-classical holographic wormhole
corresponds to a rather special property of the operator-size distributio
n we call "size winding". For more general setups (which may not have a cl
ean emergent geometry)\, we argue that imperfect size winding is a general
ization of the traversable wormhole phenomenon. For example\, a form of si
gnalling continues to function at high temperature and at large times for
generic chaotic systems\, even though it does not correspond to a signal g
oing through a geometrical wormhole\, but rather to an interference effect
involving macroscopically different emergent geometries. Finally\, we out
line implementations feasible with current technology in two experimental
platforms: Rydberg atom arrays and trapped ions.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hsin-Yuan (Robert) Huang (Caltech)
DTSTART;VALUE=DATE-TIME:20200417T180000Z
DTEND;VALUE=DATE-TIME:20200417T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/6
DESCRIPTION:Title: Predicting Many Properties of a Quantum System from Very Few Measurem
ents\nby Hsin-Yuan (Robert) Huang (Caltech) as part of IQIM Seminar Se
ries\n\n\nAbstract\nPredicting properties of complex\, large-scale quantum
systems is essential for developing quantum technologies. We present an e
fficient method for constructing an approximate classical description of a
quantum state using very few measurements of the state. This description\
, called a classical shadow\, can be used to predict many different proper
ties: order log(M) measurements suffice to accurately predict M different
functions of the state with high success probability. The number of measur
ements is independent of the system size and saturates information-theoret
ic lower bounds. Moreover\, target properties to predict can be selected a
fter the measurements are completed. We support our theoretical findings w
ith extensive numerical experiments. We apply classical shadows to predict
quantum fidelities\, entanglement entropies\, two-point correlation funct
ions\, expectation values of local observables\, and the energy variance o
f many-body local Hamiltonians. The numerical results highlight the advant
ages of classical shadows relative to previously known methods.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ding Zhong (Caltech)
DTSTART;VALUE=DATE-TIME:20200424T180000Z
DTEND;VALUE=DATE-TIME:20200424T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/7
DESCRIPTION:Title: Harvesting proximity effect in 2D Ferromagnetic Semiconductor Heteros
tructures for Spin and Valleytronics\nby Ding Zhong (Caltech) as part
of IQIM Seminar Series\n\n\nAbstract\nMonolayer transition metal dichalcog
enides host easily accessible spin and valley degrees of freedom that can
be used to encode and process information. With the advent of van der Waal
s heterostructures\, there are new opportunities to engineer spin and vall
eytronic devices with more advanced functionalities. In this talk\, I will
describe a van der Waals heterostructure composed of a monolayer semicond
uctor\, WSe2\, and an ultrathin layered ferromagnetic semiconductor\, CrI3
. The integration of the two materials enables a strong magnetic proximity
effect in WSe2 and spin-selective charge transfer from WSe2 to CrI3. By c
ontrolling the individual layer magnetization in CrI3 with a magnetic fiel
d\, we show that the spin-dependent charge transfer between WSe2 and CrI3
is dominated by the interfacial CrI3 layer\, while the proximity exchange
field is highly sensitive to the layered magnetic structure as a whole. Th
ese properties allow us to achieve unprecedented control of WSe2 valley pr
operties in these devices. Moreover\, the photoluminescence detection of W
Se2 valley pseudospin provides us with a simple yet powerful tool to probe
the layer-resolved magnetization dynamics in CrI3.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ash Milsted (Caltech)
DTSTART;VALUE=DATE-TIME:20200508T180000Z
DTEND;VALUE=DATE-TIME:20200508T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/8
DESCRIPTION:Title: Simulating the collapse of false-vacuum bubbles in spin chains\nb
y Ash Milsted (Caltech) as part of IQIM Seminar Series\n\n\nAbstract\nIt i
s possible that we live close to a local energetic minimum of the Standard
Model\, with an ever-present chance of catastrophic decay to the true min
imum. We study the real-time collapse of a small bubble of false vacuum\,
on a true-vacuum background\, in the vastly simpler setting of 1+1-dimensi
onal spin chains\, which nevertheless can capture key aspects if the physi
cs involved. We construct spatially localized false-vacuum bubbles using a
n infinite Matrix Product State ansatz and simulate their time evolution\,
demonstrating inelastic scattering when the walls of the bubbles collide
in an Ising-like chain. In contrast\, the simplest candidate model -- the
unmodified transverse-field Ising model with a small longitudinal field --
is seen to exhibit only elastic scattering\, so that false-vacuum bubbles
merely bounce back after collapsing.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wilbur Shirley (Caltech)
DTSTART;VALUE=DATE-TIME:20200515T180000Z
DTEND;VALUE=DATE-TIME:20200515T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/9
DESCRIPTION:Title: Fractonic order\nby Wilbur Shirley (Caltech) as part of IQIM Semi
nar Series\n\n\nAbstract\nIn recent years\, a theoretical new class of thr
ee-dimensional gapped phases of quantum matter has risen to the fore. Thes
e phases\, originally discovered in the search for a self-correcting quant
um memory\, are said to exhibit fractonic order --- a novel form of long-r
ange entanglement similar to intrinsic topological order\, but distinct fr
om it due to a striking dependence of the universal properties of a phase
on lattice geometry. This dependence manifests in a number of exotic featu
res including fractional excitations with constrained mobility\, unusually
slow thermalization dynamics\, and ground state degeneracy that grows wit
h system size. In this talk\, I will give an introduction to the topic\, a
nd describe recent progress towards a systematic understanding of these ph
ases in terms of emergent gauge theory and entanglement renormalization gr
oup flow.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Junyu Liu (Caltech)
DTSTART;VALUE=DATE-TIME:20201009T180000Z
DTEND;VALUE=DATE-TIME:20201009T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/10
DESCRIPTION:Title: Quantum computation and “cyberpunkian” quantum field theory\
nby Junyu Liu (Caltech) as part of IQIM Seminar Series\n\n\nAbstract\nQuan
tum field theory is one of the greatest achievements by human beings in un
derstanding the law of the universe. Almost all subjects in modern physics
\, from condensed-matter physics to string theory\, are closely related to
the developments of quantum field theory. However\, Established in the in
finite-dimensional Hilbert spaces\, quantum field theory is very hard to s
tudy\, especially when the theory is strongly coupled.\n\nThis talk is a s
ummary of quantum opportunities for solving quantum field theory theoretic
ally and numerically\, based on a series of works by the speaker and colla
borators. Specifically\, we describe a digital quantum simulation algorith
m for simulating domain wall scatterings in the 1+1 dimensional quantum fi
eld theory\, which could be regarded as a toy version of cosmological fals
e vacuum decay in the real universe\, as an example. We will discuss some
potential fundamental limitations of classical algorithms\, how quantum co
mputers will help us solve the problem\, and how good quantum computers ar
e (the quantum-extended Church-Turing Thesis). Moreover\, we will discuss
some great classical algorithms developed in recent years. Namely\, matrix
product states in quantum many-body systems (tensor networks) and semidef
inite programming in conformal field theories (the conformal bootstrap).\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yingfei Gu (Caltech)
DTSTART;VALUE=DATE-TIME:20201016T180000Z
DTEND;VALUE=DATE-TIME:20201016T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/11
DESCRIPTION:Title: Scrambling and Branching\nby Yingfei Gu (Caltech) as part of IQI
M Seminar Series\n\n\nAbstract\nOut-of-time-order correlators (OTOCs) desc
ribe quantum chaos in a way comparable to classical chaos\, at least for s
ystems with a large parameter N\, where the early-time OTOCs are character
ized by a Lyapunov exponent\, whose inverse defines a time scale known as
Lyapunov time. In this talk\, I will discuss another time scale called bra
nching time and derive a bound on it for SYK-like models. It turns out tha
t the branching time plays significantly different roles in the strong and
weak coupling limits\, suggesting two different mechanisms for scrambling
. This talk is based on [1812.00120] with Alexei Kitaev and work in progre
ss with Alexei Kitaev and Pengfei Zhang.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cyprian Lewandowski (Caltech)
DTSTART;VALUE=DATE-TIME:20201023T180000Z
DTEND;VALUE=DATE-TIME:20201023T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/12
DESCRIPTION:Title: Pairing in magic-angle twisted bilayer graphene: role of phonon and
plasmon umklapp\nby Cyprian Lewandowski (Caltech) as part of IQIM Semi
nar Series\n\n\nAbstract\nIdentifying the microscopic mechanism for superc
onductivity in magic-angle twisted bilayer graphene (MATBG) is an outstand
ing open problem. While MATBG exhibits a rich phase-diagram\, driven partl
y by the strong interactions relative to the electronic bandwidth\, its si
ngle-particle properties are unique and likely play an important role in s
ome of the phenomenological complexity. Some of the salient features inclu
de an electronic bandwidth smaller than the characteristic phonon bandwidt
h and a non-trivial structure of the underlying Bloch wavefunctions. In th
is talk\, I will discuss a theoretical study of the cooperative effects du
e to phonons and plasmons on pairing in order to disentangle the distinct
role played by these modes on superconductivity. We will consider a varian
t of MATBG with an enlarged number of fermion flavors\, N≫1\, where the
study of pairing instabilities reduces to the conventional (weak-coupling)
Eliashberg framework. In particular\, I will show that certain umklapp pr
ocesses involving mini-optical phonon modes\, which arise physically as a
result of the folding of the original acoustic branch of graphene due to t
he moiré superlattice structure\, contribute significantly towards enhanc
ing pairing. Time permitting\, I will also consider the role played by the
dynamics of the screened Coulomb interaction on pairing\, which leads to
an enhancement in a narrow window of fillings\, and study the effect of ex
ternal screening due to a metallic gate on superconductivity. Finally\, I
will propose a smoking-gun experiment to detect resonant features associat
ed with the phonon-umklapp processes in the differential conductance and a
lso discuss several experimental implications of a pairing mechanisms rely
ing on plasmons.\n\nThe talk will follow a joint work with Debanjan Chowdh
ury and Jonathan Ruhman\, available at arXiv:2007.15002\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuan Su (Caltech)
DTSTART;VALUE=DATE-TIME:20201030T180000Z
DTEND;VALUE=DATE-TIME:20201030T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/13
DESCRIPTION:Title: A Theory of Trotter Error\nby Yuan Su (Caltech) as part of IQIM
Seminar Series\n\n\nAbstract\nWe develop a theory of Trotter error that ov
ercomes the limitations of prior approaches based on truncating the Baker-
Campbell-Hausdorff expansion. Our analysis directly exploits the commutati
vity of operator summands\, producing tighter error bounds for both real-
and imaginary-time evolutions. Whereas previous work achieves similar goal
s for systems with Lie-algebraic structure or certain low-order formulas\,
our approach holds in general.\nWe give a host of improved algorithms for
digital quantum simulation and quantum Monte Carlo methods\, including si
mulations of nearest-neighbor lattice Hamiltonians\, second-quantized plan
e-wave electronic structure\, $k$-local Hamiltonians\, rapidly decaying po
wer-law interactions\, clustered Hamiltonians\, the transverse field Ising
model\, and quantum ferromagnets\, nearly matching or even outperforming
the best previous results.\nWe obtain further speedups using the fact that
product formulas can preserve the locality of the simulated system. Speci
fically\, we show that local observables can be simulated with complexity
independent of the system size for power-law interacting systems\, which i
mplies a Lieb-Robinson bound as a byproduct.\nOur analysis reproduces know
n tight bounds for first- and second-order formulas. Our higher-order boun
d overestimates the complexity of simulating a one-dimensional Heisenberg
model with an even-odd ordering of terms by only a factor of 5\, and is cl
ose to tight for power-law interactions and other orderings of terms. This
suggests that our theory can accurately characterize Trotter error in ter
ms of both asymptotic scaling and constant prefactor.\n\nBased on arXiv:19
01.00564 and arXiv:1912.08854.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chaitali Joshi (Caltech)
DTSTART;VALUE=DATE-TIME:20201106T190000Z
DTEND;VALUE=DATE-TIME:20201106T200000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/14
DESCRIPTION:Title: Quantum photonics with color qubits\nby Chaitali Joshi (Caltech)
as part of IQIM Seminar Series\n\n\nAbstract\nOptical photons are excelle
nt flying qubits for long-distance quantum networks due to negligible ther
mal noise and decoherence at room temperature. In this talk\, I will discu
ss how frequency encoding can be combined with nonlinear optics and fiber
and integrated photonic technologies to address challenges in scaling futu
re photonic quantum networks. Frequency multiplexing has had a profound im
pact on classical telecommunication networks\, creating low loss and inexp
ensive hardware that can be exploited for quantum applications. I will des
cribe quantum photonic applications where frequency encoding provides a di
stinct advantage in terms of scaling losses and resource overhead compared
to polarization\, spatial or temporal mode encoding. \n\nCoherent manipul
ation of light in the frequency domain at the single-photon level requires
a strong\, noise-free nonlinear process. I will discuss our implementatio
n of four-wave mixing (FWM) in a commercial dispersion-shifted fiber to ac
hieve quantum frequency conversion with near-unity efficiency and low nois
e. I will discuss how we used this process as an active "frequency switch"
to realize a low-loss multiplexed single-photon source that can be scaled
to the deterministic regime. Next\, I will discuss how we used this proce
ss as a frequency beam-splitter to demonstrate two-photon Hong-Ou-Mandel t
ype interference between entangled photons of different colors- a hallmark
of quantum indistinguishability. Finally\, I will discuss our realization
of a FWM-based "time lens" for the generation and detection of single-pho
ton waveforms with picosecond resolution. \n\nBased on Joshi et al.\, Nat
. Comm. 9\, 847 (2018)\, Joshi et al. Phys. Rev. Lett. 124\, 143601(2020)\
n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chi Fang (Anthony) Chen (Caltech)
DTSTART;VALUE=DATE-TIME:20201113T190000Z
DTEND;VALUE=DATE-TIME:20201113T200000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/15
DESCRIPTION:Title: Hierarchy of light cones in power-law interacting systems: review of
recent bounds and saturating protocols\nby Chi Fang (Anthony) Chen (C
altech) as part of IQIM Seminar Series\n\n\nAbstract\nIn quantum many-body
systems with local interactions\, quantum information and entanglement ca
nnot spread outside of a linear light cone\, which expands at an emergent
velocity analogous to the speed of light. Though\, realistic systems often
have a power-law interaction $1/r^α$. In this talk\, we discuss a hierar
chy of light cones in these long-ranged systems: At the same α\, some qua
ntum information processing tasks are constrained by a `linear’ light co
ne\, while others are not. In one spatial dimension\, a linear light cone
exists for every many-body state when α > 3 (Lieb-Robinson light cone)\;
for a typical state chosen uniformly at random when α > 5/2 (Frobenius li
ght cone)\; and for every state of a noninteracting system when α > 2 (fr
ee light cone). These bounds apply to time-dependent systems and are satur
ated by explicit protocols. Some of these linear light cones extend to alg
ebraic ones and/or generalize to higher dimensions. As an example among t
he various implications\, universal quantum state transfer\, as well as ma
ny-body quantum chaos\, is bounded by the Frobenius light cone and\, there
fore\, is poorly constrained by all Lieb-Robinson bounds. This talk will b
e an up-to-date review over regimes of α\, recent protocols and the key p
hysical intuitions and the high-level proof ideas.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:TBA
DTSTART;VALUE=DATE-TIME:20201120T190000Z
DTEND;VALUE=DATE-TIME:20201120T200000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/16
DESCRIPTION:by TBA as part of IQIM Seminar Series\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Xin Xie (Caltech)
DTSTART;VALUE=DATE-TIME:20201204T190000Z
DTEND;VALUE=DATE-TIME:20201204T200000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/17
DESCRIPTION:Title: Precise Calibrations of Few-Body Physics in Potassium-39\nby Xin
Xie (Caltech) as part of IQIM Seminar Series\n\n\nAbstract\nWe perform pr
ecise studies of two-and three-body interactions near an intermediate-stre
ngth Feshbach resonance in potassium-39 at 33.5820(14) G. Precise measurem
ent of dimer binding energies enables the construction of a complete two-b
ody coupled-channel model for determination of the scattering lengths with
an unprecedented low uncertainty. Utilizing such an accurate scattering l
ength map\, we unambiguously locate four distinct features in the Efimov t
hree-body structure. Meticulous characterization of and correction for fin
ite temperature effects ensure high accuracy on the measurements of these
features at large-magnitude scattering lengths. We report the ground Efimo
v resonance location to be at −14.05(17) times the van der Waals length
r_vdW\, significantly deviating from the value of −9.7r_vdW predicted by
van der Waals universality [1]. While three of these features form ratios
that obey the Efimov universal scaling to within 10% [2].\n\n[1] https://
journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.233402\n[2] https://
journals.aps.org/prl/accepted/94071Yb5H8819f8421972b1289f4d229daf32da51\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Natalie Klo (Caltech)
DTSTART;VALUE=DATE-TIME:20201218T190000Z
DTEND;VALUE=DATE-TIME:20201218T200000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/19
DESCRIPTION:Title: Post-Anthropocene Computation: Rewilding the Quantum Field\nby N
atalie Klo (Caltech) as part of IQIM Seminar Series\n\n\nAbstract\nWhether
interested in simulating dynamical interactions of fundamental particles
or otherwise implementing a large-scale quantum computation\, the field th
eoretic framework of spatially distributed quantum degrees of freedom is i
nvaluable. By leveraging their natural capacity to describe highly entangl
ed many-body states\, the use of atomic-scale quantum systems to form a co
mputational framework for the exploration of sub-atomic phenomena is envis
ioned to be non-perturbatively advantageous. In this talk\, I will share a
developing perspective on the entanglement structures within quantum fiel
ds and discuss resulting implications for the design of effective field th
eories and future practical quantum simulations of quantum fields.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Harry Levine (Harvard)
DTSTART;VALUE=DATE-TIME:20201028T180000Z
DTEND;VALUE=DATE-TIME:20201028T190000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/20
DESCRIPTION:Title: Quantum simulation and quantum computation with programmable Rydberg
atom arrays\nby Harry Levine (Harvard) as part of IQIM Seminar Series
\n\n\nAbstract\nNeutral atom arrays form a powerful platform for studying
and coherently controlling many-body quantum systems. These arrays can be
readily scaled to hundreds of individually controlled atoms with flexible\
, programmable geometries. Strong atomic interactions can be introduced by
coherent excitation to Rydberg states\, resulting in a rich spin Hamilton
ian with variable interaction range\, as well as tools for quantum informa
tion processing. In this talk\, I will discuss two applications of coheren
t control over 1D atom arrays to create and benchmark entangled states. In
the first\, we utilize the Rydberg Hamiltonian to globally drive a 20 ato
m array into a fully entangled Schrödinger cat state. In the second\, we
introduce a new protocol for a universal two-qubit gate on neutral atoms\,
and demonstrate its parallel implementation on several pairs of qubits. F
inally\, I will discuss our ongoing work scaling our system to 2D arrays o
f hundreds of qubits\, including preliminary results exploring the phase d
iagram of 2D arrays as well as applications to graph theory optimization p
roblems.\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:TBA
DTSTART;VALUE=DATE-TIME:20210108T190000Z
DTEND;VALUE=DATE-TIME:20210108T200000Z
DTSTAMP;VALUE=DATE-TIME:20240715T182125Z
UID:IQIM-seminar/21
DESCRIPTION:by TBA as part of IQIM Seminar Series\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/IQIM-seminar/21/
END:VEVENT
END:VCALENDAR