Bulletin of the American Physical Society
APS March Meeting 2017
Volume 62, Number 4
Monday–Friday, March 13–17, 2017; New Orleans, Louisiana
Session P46: Implementing Quantum Algorithms in Experimental SystemsFocus
|
Hide Abstracts |
Sponsoring Units: GQI Chair: John Martinis, Google and University of California, Santa Barbara Room: 393 |
Wednesday, March 15, 2017 2:30PM - 3:06PM |
P46.00001: Challenges ahead in implementing digital quantum algorithms Invited Speaker: Rami Barends Superconducting qubits are starting to demonstrate quantum algorithms consisting of up to a thousand gates, a size that can be considered as a precursor to future large-scale algorithms. These demonstrations highlight the need for improvements in hardware, specifically in control, fidelity, and coherence. I will discuss the present limitations and the challenges ahead in improving quantum hardware to enable larger algorithms. [Preview Abstract] |
Wednesday, March 15, 2017 3:06PM - 3:42PM |
P46.00002: An extensible circuit QED architecture for quantum computation Invited Speaker: Leo DiCarlo Realizing a logical qubit robust to single errors in its constituent physical elements is an immediate challenge for quantum information processing platforms. A longer-term challenge will be achieving quantum fault tolerance, i.e., improving logical qubit resilience by increasing redundancy in the underlying quantum error correction code (QEC). In QuTech, we target these challenges in collaboration with industrial and academic partners. I will present the circuit QED quantum hardware, room-temperature control electronics, and software components of the complete architecture. I will show the extensibility of each component to the Surface-17 and -49 circuits needed to reach the objectives with surface-code QEC, and provide an overview of latest developments. [Preview Abstract] |
Wednesday, March 15, 2017 3:42PM - 3:54PM |
P46.00003: White-box and black-box macromodeling for superconducting quantum circuits [Part I] Michael Scheer, Maxwell Block, Eyob Sete, Nick Rubin, Nikolas Tezak, Matt Reagor, Chad Rigetti As superconducting qubit architectures increase in size and complexity, the ability to build and analyze numerical quantum mechanical models of global chip parameters is becoming increasingly important. White-box models, in which the circuit topology is assumed known, are useful for finding the mapping between geometrical design parameters and Hamiltonian parameters. In contrast, black-box models (e.g. Foster’s or Brune’s circuit synthesis methods) hide the connection between geometry and Hamiltonian parameters, though they can be far more accurate. In this talk we present a unified framework for building and analyzing white-box and black-box models of superconducting circuits. [Preview Abstract] |
Wednesday, March 15, 2017 3:54PM - 4:06PM |
P46.00004: White-box and black-box macromodeling for superconducting quantum circuits [Part II] Maxwell Block, Michael Scheer, Eyob Sete, Nick Rubin, Nikolas Tezak, Matt Reagor, Chad Rigetti Modeling and simulation tools enable more rapid exploration of the superconducting quantum circuit parameter space than would be possible with fabrication and measurement alone. A variety of modeling schemes for these circuits have been proposed. However, experimental studies of these schemes are required to determine their regimes of applicability. In this talk we compare several modeling techniques to the measured parameters of many qubits. We evaluate these models in terms of their accuracy and resource requirements and discuss their utility for designing many-qubit systems. [Preview Abstract] |
Wednesday, March 15, 2017 4:06PM - 4:18PM |
P46.00005: Scheduling Quantum Programs Robert Smith, Michael Curtis, Anthony Polloreno, Nicholas Rubin, Nikolas Tezak, Will Zeng In compiling quantum circuits it can be analytically convenient to assume each gate takes the same amount of physical time and to set our unit time step to the maximum gate time. However, as is the case on quantum computers based on superconducting qubits, each gate takes a certain distinct amount of time, which leads to the possibility of additional optimization. In this talk, we formalize the notion of gate times using quantum abstract machines as a foundation, and introduce methods to optimize gate scheduling via temporally dense parallelization using black-box information (i.e., no knowledge of the structure of the gate pulses) and white-box information (i.e., knowledge of the geometry of the gate pulses over time). [Preview Abstract] |
Wednesday, March 15, 2017 4:18PM - 4:30PM |
P46.00006: Random Quantum Circuits with Varying Topologies and Gate Sets Anthony Polloreno, Nicholas Rubin, Robert Smith, William Zeng We build on recent results using sampling from the output of random unitary matrices as a metric for quantum supremacy. We first investigate the relationship between the choice of gate set and the circuit depth required to converge to the Porter-Thomas distribution. In particular, we note that convergence is possible using iSWAP gates in place of CZ gates. Next we explore the effects of varying qubit connectivity on the convergence behavior of random circuits. We address the feasibility of these schemes with near-term superconducting qubit hardware. [Preview Abstract] |
Wednesday, March 15, 2017 4:30PM - 4:42PM |
P46.00007: A Hybrid Classical/Quantum Approach for Large-Scale Studies of Quantum Systems with Density Matrix Embedding Theory Nicholas Rubin Determining ground state energies of quantum systems by hybrid classical/quantum methods has emerged as a promising candidate application for near-term quantum computational resources. Short of large-scale fault-tolerant quantum computers, small-scale devices can be leveraged with current computational techniques to identify important subspaces of relatively large Hamiltonians. Inspired by the work that described the merging of dynamical mean-field theory (DMFT) with a small-scale quantum computational resource as an impurity solver~[Bauer et al., arXiv:1510.03859v2], we describe an alternative embedding scheme, density matrix embedding theory (DMET), that naturally fits with the output from the variational quantum eigensolver and other hybrid approaches. This approach is validated using a quantum abstract machine simulator~[Smith~et al., arXiv:1608.03355] that reproduces the ground state energy of the Hubbard model converged to the infinite limit. We comment on the implementation of this algorithm in near-term superconducting processors. [Preview Abstract] |
Wednesday, March 15, 2017 4:42PM - 4:54PM |
P46.00008: QASM 2.0: A Quantum Circuit Intermediate Representation Lev S. Bishop A quantum circuit is a sequence of unitary operations and measurements to be performed on a quantum state (where later operations may be conditional on earlier measurement results). As a mathematical abstraction, a circuit is a POVM; and at a hardware implementation level it is the sequence of signals that are sent to and from a physical quantum device. In between these two extremes there is a need for a representation where one can reason about optimization, mapping of abstract algorithms under device constraints, etc. We present a specification for a minimal, architecture-independent, extensible language suitable for such circuit-rewriting tasks. We also discuss our application of this language, QASM 2.0, to recent superconducting qubit experiments, as well as related software tools. This language currently has real-world use, serving as the interface to the IBM Quantum Experience, a publicly-accessible cloud quantum processor demonstration platform. [Preview Abstract] |
Wednesday, March 15, 2017 4:54PM - 5:06PM |
P46.00009: ProjectQ Software Framework Damian S. Steiger, Thomas Haener, Matthias Troyer Quantum computers promise to transform our notions of computation by offering a completely new paradigm. A high level quantum programming language and optimizing compilers are essential components to achieve scalable quantum computation. In order to address this, we introduce the ProjectQ software framework -- an open source effort to support both theorists and experimentalists by providing intuitive tools to implement and run quantum algorithms. Here, we present our ProjectQ quantum compiler, which compiles a quantum algorithm from our high-level Python-embedded language down to low-level quantum gates available on the target system. We demonstrate how this compiler can be used to control actual hardware and to run high-performance simulations. [Preview Abstract] |
Wednesday, March 15, 2017 5:06PM - 5:18PM |
P46.00010: ProjectQ: Compiling quantum programs for various backends Thomas Haener, Damian S. Steiger, Matthias Troyer In order to control quantum computers beyond the current generation, a high level quantum programming language and optimizing compilers will be essential. Therefore, we have developed ProjectQ -- an open source software framework to facilitate implementing and running quantum algorithms both in software and on actual quantum hardware. Here, we introduce the backends available in ProjectQ. This includes a high-performance simulator and emulator to test and debug quantum algorithms, tools for resource estimation, and interfaces to several small-scale quantum devices. We demonstrate the workings of the framework and show how easily it can be further extended to control upcoming quantum hardware. [Preview Abstract] |
Wednesday, March 15, 2017 5:18PM - 5:30PM |
P46.00011: Investigations of quantum heuristics for optimization Eleanor Rieffel, Stuart Hadfield, Zhang Jiang, Salvatore Mandra, Davide Venturelli, Zhihui Wang We explore the design of quantum heuristics for optimization, focusing on the quantum approximate optimization algorithm, a metaheuristic developed by Farhi, Goldstone, and Gutmann. We develop specific instantiations of the of quantum approximate optimization algorithm for a variety of challenging combinatorial optimization problems. Through theoretical analyses and numeric investigations of select problems, we provide insight into parameter setting and Hamiltonian design for quantum approximate optimization algorithms and related quantum heuristics, and into their implementation on hardware realizable in the near term. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700