aspuru-list February 2019

aspuru-list@lists.fas.harvard.edu

12 participants
31 discussions

[Aspuru-Guzik Group List] [qip] Another talk today at Harvard: Wormholes and Entanglement

by Jon Tyson

Maldacena is speaking today, although it conflicts with Cirac's talk: Joint Harvard-MIT STR SEM/Black Holes: Juan Maldacena, IAS Wormholes and entanglement Wednesday, February 27⋅4:00 – 6:00pm Austin East 101 (Harvard Law School) <https://maps.google.com/maps?hl=en&q=Austin%20East%20101%20%28Harvard%20Law…> We discuss some wormhole-like solutions of general relativity that look like black holes from the outside. We recall the idea that black holes can be viewed as ordinary quantum systems when viewed from the outside. Then these wormholes can be viewed as entangled states. Finally we will discuss the conditions under which they can become traversable. We will mention some implications of this idea for black hole information paradoxes. _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

5 years, 1 month

[Aspuru-Guzik Group List] Reminder TODAY: Joint Quantum Seminar - Wednesday, February 27, 2018 @ 4:00 - Prof. Ignacio Cirac

by Dakoulas, Samantha R

Joint Quantum Seminar Wednesday, February 27, 2019 4:00 PM, Jefferson 250 Prof. Ignacio Cirac, Max-Planck-Institut für Quantenoptik “Quantum algorithms and simulation for quantum many-body systems” Quantum many-body systems are very hard to simulate, as computational resources (time and memory) typically grow exponentially with system size. However, quantum computers or analog quantum simulators may perform that task in a much more efficient way. In this talk, I will first review some of the quantum algorithms that have been proposed for this task and then explain the advantages and disadvantages of analog quantum simulators. I will also describe a theoretical proposal to solve quantum chemistry problems with such devices. Student Presentation will begin at 4:00 (Yao Wang – “Pump-Induced Superconductivity and Higgs Oscillations”) Guest Presentation will begin at 4:30 PM Refreshments will be provided Samantha Dakoulas Faculty Assistant to Professors Lukin & Greiner & their groups Department of Physics 17 Oxford St., Lyman 324A Cambridge, MA 02138 P. (617) 496-2544

5 years, 1 month

[Aspuru-Guzik Group List] [qip] Fwd: CFP - Workshop On Quantum Resource Estimation (QRE 2019)

by Aram Harrow

---------- Forwarded message --------- From: Alexandru Paler <alexandrupaler(a)gmail.com> Date: Fri, Feb 22, 2019 at 9:22 AM Subject: CFP - Workshop On Quantum Resource Estimation (QRE 2019) To: <qcit(a)comsoc.org> --= Call for Papers =-- 1st International Workshop on Quantum Resource Estimation (QRE 2019) June 22, 2019, Phoenix, AZ, USA co-located with International Symposium on Computer Architecture (ISCA) 2019 https://www.quantumresource.org/ ======================================================================= Quantum computation has a growing number of promising application areas such as quantum chemistry, quantum optimisation and finance. However, the first industrially relevant and scalable quantum computer seems to be at least a decade away. Therefore, one of the most pressing questions is "How many physical qubits and how much time is necessary to execute a quantum algorithm on a selected hardware platform where the algorithmic output is more important than the fact a quantum computer was used to calculate it?" By examining this question in depth we can motivate continued investment for quantum computing, further enable resource friendly quantum algorithm development and continue to push technological advances that will lead to a scalable quantum computing ecosystem. The workshop will bring together researchers to discuss new methods and directions needed to develop, as soon as possible, the tools to: * accurately analyze and benchmark complex quantum algorithms * adapt error-correction techniques * refine classical control and hardware microarchitectures * enable scientifically and commercially relevant quantum applications Research papers, tutorials, software and other demonstrations, and work-in-progress reports are within the scope of the workshop. Invited talks by leading international experts will complete the program. Contributions on all areas of quantum performance analytics are welcome: * High level quantum circuit analytics. * Fault-tolerant quantum circuit analytics. * Clifford+T optimisation strategies. * Resource efficient surface code implementations. * Surface code decoders. * Practical quantitative analysis of surface code alternatives. * Noisy Intermediate Scale Quantum (NISQ) evaluation. ===== Paper submission ===== Initial submission for QRE2019 will consist of an extended abstract, limited to 2+epsilon-pages (including figures and references, please don't go nuts with the epsilon!). Contributions must be written in English and report on original, unpublished work, not submitted for publication elsewhere. Upon acceptance, researchers are invited to submit full research papers (maximum 12 pages), as well as work-in-progress or tool demonstration papers (maximum 6 pages). Accepted full papers will be published in a journal (subject to the journal being approved - IEEE Transactions on Quantum Engineering; otherwise a backup journal TBD exists). https://easychair.org/conferences/?conf=qre2019 ===== Important Dates ===== Extended Abstract Submission: 21 April 2019 Notification Extended Abstract: 12 May 2019 Workshop Date: 22 June 2019 Full Paper Submission: 1 August 2019 Notification of Full Paper: (tentative) 1 November 2019 Publication of Full Paper: (tentative) 1 January 2020 ------------------------------ To unsubscribe from the qcit list, click the following link: https://comsoc-listserv.ieee.org/cgi-bin/wa?SUBED1=qcit&A=1 _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

5 years, 1 month

[Aspuru-Guzik Group List] [qip] Ignacio Cirac Wednesday Fwd: Joint Quantum Seminar - Feb 27

by Jon Tyson

---------- Forwarded message --------- From: Tariri, Naomi <ntariri(a)cfa.harvard.edu> Date: Tue, Feb 26, 2019 at 10:12 AM Subject: Joint Quantum Seminar - Feb 27 To: <bapc-late(a)cosmos.phy.tufts.edu> 4:30 pm Wednesday, Feb 27, 2019 Joint Quantum Seminar Jefferson 250, Harvard University, Department of Physics Prof. Ignacio Cirac Max-Planck-Institut für Quantenoptik “Quantum algorithms and simulation for quantum many-body systems” _______________________________________________ bapc mailing list http://cosmos.phy.tufts.edu/bapc.html _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

5 years, 1 month

[Aspuru-Guzik Group List] Joint Quantum Seminar - Wednesday, February 27, 2018 @ 4:00 - Prof. Ignacio Cirac

by Dakoulas, Samantha R

5 years, 1 month

[Aspuru-Guzik Group List] Special Physics Seminar: Ruichao (Alex) Ma

by Ploucha, Clare

Ruichao (Alex) Ma PhD, Harvard University 2014 Postdoctoral Fellow, University of Chicago “Exploring Synthetic Quantum Matter in Superconducting Circuits” Tuesday, February 26, 9:00am Jefferson 256 Abstract: Understanding strongly correlated materials is an outstanding challenge in modern physics. Synthetic quantum matter, tailor-made in the lab as clean, tunable and easy to probe quantum simulators, can help us gain insights into such strongly correlated matter, and explore new parameter regimes with no natural counterpart. In this talk, I will show how we create and explore quantum materials made of light, specifically microwave photons trapped in superconducting circuits. We develop a new approach for preparing many-body phases, where engineered dissipation is used as a resource to protect the fragile quantum states against intrinsic losses. We apply it to our system, a strongly interacting Bose-Hubbard lattice, and realize a dissipatively stabilized Mott insulator of photons. The dynamics of thermalization towards the Mott phase is probed using lattice-site- and time- resolved microscopy. Our experiments establish superconducting circuits as a powerful platform for studying quantum materials, and open many future possibilities including the exploration of strongly interacting topological phases, quantum thermodynamics in coherent or driven-dissipative settings, and hybrid quantum systems with exotic couplings.

5 years, 1 month

[Aspuru-Guzik Group List] [qip] Seminar: entropic uncertainty relations + scrambling

by Nicole Yunger Halpern

Hi, quanta, I’m giving an ITAMP Seminar about entropic uncertainty relations for quantum-information scrambling at Harvard this Thursday. Come early for free pizza! See below for details. Best, Nicole -- Nicole Yunger Halpern ITAMP Postdoctoral Fellow Harvard-Smithsonian Institute for Theoretical Atomic, Molecular, and Optical Physics (ITAMP) Harvard University Department of Physics nicoleyh.11(a)gmail.com *Entropic uncertainty relations for quantum-information scrambling* *Abstract*: How violently do two quantum operators disagree? Different subfields of physics feature different notions of incompatibility: (i) In quantum information theory, uncertainty relations are cast in terms of entropies. These e*ntropic uncertainty relations* constrain measurement outcomes. (ii) Condensed matter and high-energy physics feature interacting quantum many-body systems, such as spin chains. A local perturbation, such as a Pauli operator on one side of a chain, spreads through many-body entanglement. The perturbation comes to overlap, and to disagree, with probes localized on the opposite side of the system. This disagreement signals that quantum information about the perturbation has *scrambled*, or become hidden in highly nonlocal correlations. I will unite these two notions of quantum operator disagreement, presenting an entropic uncertainty relation for quantum-information scrambling. The entropies are of distributions over weak and strong measurements’ possible outcomes. The uncertainty bound strengthens when a spin chain scrambles in numerical simulations. Hence the subfields—quantum information, condensed matter, and high-energy physics—can agree about when quantum operations disagree. Our relation can be tested experimentally with superconducting qubits, trapped ions, and quantum dots. NYH, Bartolotta, and Pollack, accepted by Comms. Phys. (in press) arXiv:1806.04147 (arXiv manuscript to be updated this week). *Time*: Thurs., 2/28/19, 12-1 PM *Location: *B-106 at Harvard-Smithsonian Center for Astrophysics (CfA, 60 Garden Street <https://maps.google.com/?q=60+Garden+Street&entry=gmail&source=g>) *Directions: *After entering the lobby of the CfA, turn right to enter the hallway of the B building. In the hallway, turn right again, B-106 will be at the end of the hallway on the left side. _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

5 years, 1 month

[Aspuru-Guzik Group List] ITAMP lunch seminar - Shmuel Bialy, CFA (February 21th)

by Zolfaghari Jooya, Hossein

*Speaker:* Shmuel Bialy (Center For Astrophysics) *Date:* Thursday, February 21th *Time:* 12:00-1:00 pm Includes Pizza. *Title: *The Multiphase HI Gas - from Solar to Low Metallicities *Abstract: *The neutral atomic ISM is found to be multiphased, composed of the cold neutral medium (CNM, T ~100 K) and the warm neutral medium (WNM, T ~ 10^4 K), which coexist at approximately the same thermal pressure. Such a multiphase structure is predicted by models of heating-cooling thermal balance, where heating is dominated by photoelectric heating from dust-grains (and/or cosmic-ray heating), and cooling by Ly\alpha line emission (for the WNN, T ~10^4 K) and [C II] and [O I] line-emission (for the CNM, T ~100 K). Intermediate temperatures are thermally unstable. The multiphase phenomena and the thermal instability zone, may play a key role in regulating the star-formation properties in galaxies. I will present recent results (Bialy & Sternberg, in prep) discussing the thermal properties of HI gas, as functions of the UV intensity, the cosmic-ray ionization rate, and gas metallicity, from solar to primordial metallicities.I will discuss the importance of the residual H2 in controlling the thermal structure of the predominantly HI gas. Despite its low equilibrium abundance (H2/HI ~ 10^{-6}), we find that H2 cooling and heating mechanisms (dominated by H2 ro-vibrational cooling, UV pumping heating, and H2 formation heating) strongly affect (or totally dominate) the phase structure at low metallicities and/or when the UV intensity to cosmic-ray ionization rate ratio is low. *Location: *B-106 @ Center for Astrophysics (60 Garden Street <https://maps.google.com/?q=60+Garden+Street&entry=gmail&source=g>) *Directions: *After entering the lobby of the CfA, turn right to enter the hallway of the B building. In the hallway, turn right again, B-106 will be at the end of the hallway on the left side.

5 years, 1 month

[Aspuru-Guzik Group List] Hannes Pichler: Tuesday, February 19, 2019, 9:00am, in Jefferson 356

by Ploucha, Clare

Hannes Pichler PhD, University of Innsbruck, Austria Tuesday, February 19, 2019, 9:00am Jefferson 356 From many-body physics to quantum information with atomic and photonic systems Quantum many-body systems have unique properties that give rise to fascinating phenomena and potential applications, ranging from exotic phases of matter to new paradigms for information processing and communication. Quantum optical systems allow to engineer such quantum many-body systems in a controlled, bottom-up approach. This enables new ways to create and probe states of matter but also poses new theoretical challenges for describing them. I will illustrate this in my talk on a few examples. I will first discuss the many-body quantum phenomena associated with arrays of trapped Rydberg atoms. This includes the equilibrium quantum phase diagram and the quantum critical behavior, as well as novel non-equilibrium phenomena such as quantum many-body scars. Moreover, I will show how these systems can be used to naturally encode combinatorial optimization problems and realize quantum optimization algorithms. In the last part of my talk I will discuss new approaches to quantum information processing with photonic systems. In particular, I will introduce delayed quantum feedback as a novel tool to create highly entangled photon states, and show that it enables universal quantum computation already with a single quantum emitter.

5 years, 2 months

[Aspuru-Guzik Group List] TODAY - HQI Special Seminar - Di Zhu

by Ploucha, Clare

Harvard Quantum Initiative Special Seminar Friday, February 15 3:00 PM Jefferson 250 Di Zhu, MIT Title: Exploiting the microwave properties of superconducting nanowires for advancing single-photon detection The exceptional performance of superconducting nanowire single-photon detectors (SNSPDs), including >90% detection efficiency, picosecond timing resolution, and sub-hertz dark count rate, has recently enabled many impressive demonstrations in quantum science and technology, such as the loophole-free Bell test, and record-distance quantum key distribution. However, many other quantum information processing applications, such as Boson sampling, quantum walk, and linear optical quantum computing, have more demanding requirements on photon detection, such as coincidence counting over hundreds of channels, photon number resolution, and even feed-forward operation. In this talk, we will discuss how exploiting the exotic but long-neglected microwave properties of superconducting nanowires can unlock many of these missing functionalities in SNSPDs. For example, by utilizing the slow speed of light in the nanowires, less than 2% of that in free space, we can construct delay-line-multiplexed detector arrays. From this we have demonstrated a two-terminal array architecture that is suitable for coincidence detection over large numbers of spatial modes in photonic integrated circuits, and capable of resolving photon numbers. We have further demonstrated how impedance matching of the nanowires can achieve “passive amplification” and multi-photon resolution in SNSPDs. Beyond photon detection, the nanowires may be used in diverse applications ranging from microwave coupling and switching to parametric amplification.

5 years, 2 months

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

aspuru-list February 2019