Papers

E. Farhi, J. Goldstone, S. Gutmann +1 more·Mar 17, 2017

Gate model quantum computers with too many qubits to be simulated by available classical computers are about to arrive. We present a strategy for programming these devices without error correction or compilation. This means that the number of logical...

A. Gramajo, D. Dom'inguez, M. J. S'anchez·Mar 16, 2017

We study the manipulation of quantum entanglement by periodic external fields. As an entanglement measure we compute numerically the concurrence of two flux qubits coupled inductively and/or capacitively, both driven by a dc+ac magnetic flux. Also we...

Joseph Rahamim, T. Behrle, M. Peterer +6 more·Mar 16, 2017

Superconducting circuits are well established as a strong candidate platform for the development of quantum computing. In order to advance to a practically useful level, architectures are needed which combine arrays of many qubits with selective qubi...

A. Daskin·Mar 16, 2017

In this brief paper, we go through the theoretical steps of the spectral clustering on quantum computers by employing the phase estimation and the amplitude amplification algorithms. We discuss circuit designs for each step and show how to obtain the...

Daniel Stilck França·Mar 16, 2017

We show how to obtain perfect samples from a quantum Gibbs state on a quantum computer. To do so, we adapt one of the `Coupling from the Past'-algorithms proposed by Propp and Wilson. The algorithm has a probabilistic run-time and produces perfect sa...

F. Ablayev, A. Ambainis, K. Khadiev +1 more·Mar 15, 2017

We explore multi-round quantum memoryless communication protocols. These are restricted version of multi-round quantum communication protocols. The “memoryless” term means that players forget history from previous rounds, and their behavior is obtain...

Chia-Hsien Huang, H. Goan·Mar 15, 2017

How to effectively construct robust quantum gates for time-varying noise is a very important but still outstanding problem. Here we develop a systematic method to find pulses for quantum gate operations robust against both low- and high-frequency (co...

Netta Engelhardt, S. Fischetti·Mar 15, 2017

We define a new construct in quantum field theory - the causal density matrix - obtained from the singularity structure of correlators of local operators. This object provides a necessary and sufficient condition for a quantum field theory state to h...

Keith R. Motes·Mar 15, 2017

This thesis is based upon the work I have done during my PhD candidature at Macquarie University. In this work we develop quantum technologies that are directed towards realising a quantum computer. Specifically, we have made many theoretical advance...

O. Kyriienko, A. Sørensen·Mar 14, 2017

We propose a quantum algorithm for simulating spin models based on periodic modulation of transmon qubits. Using Floquet theory we derive an effective time-averaged Hamiltonian, which is of the general XYZ class, different from the isotropic XY Hamil...

Jianwei Wang, S. Paesani, R. Santagati +8 more·Mar 13, 2017

With the help of a quantum simulator and Bayesian inference it is possible to determine the unknown Hamiltonian of a quantum system. An experiment demonstrates this using a photonic quantum simulator and a solid-state system. The efficient characteri...

Liangzhong Ruan, B. Kirby, M. Brodsky +1 more·Mar 13, 2017

Quantum entanglement shared by remote network nodes serves as a valuable resource for promising applications in distributed computing, cryptography, and sensing. However, distributing entanglement with high-quality via fiber optic routes could be cha...

H. Ekmel Ercan, J. Ghosh, D. Crow +4 more·Mar 13, 2017

The performance of quantum error correction schemes depends sensitively on the physical realizations of the qubits and the implementations of various operations. For example, in quantum dot spin qubits, readout is typically much slower than gate oper...

T. O’Brien, B. Tarasinski, B. Tarasinski +1 more·Mar 12, 2017

We present a density-matrix simulation of the quantum memory and computing performance of the distance-3 logical qubit Surface-17, following a recently proposed quantum circuit and using experimental error parameters for transmon qubits in a planar c...

D. Gagnon, F. Fillion-Gourdeau, Joey Dumont +2 more·Mar 12, 2017

This Letter demonstrates control over multiphoton absorption processes in driven two-level systems, which include, for example, superconducting qubits or laser-irradiated graphene, through spectral shaping of the driving pulse. Starting from calculat...

Dongxiao Quan, Lili Zhu, Changxing Pei +1 more·Mar 10, 2017

We design forward and backward fault-tolerant conversion circuits, which convert between the Steane code and the 15-qubit Reed–Muller quantum code so as to provide a universal transversal gate set. In our method, only seven out of a total 14 code sta...

Yasunari Suzuki, K. Fujii, M. Koashi·Mar 10, 2017

In order to realize fault-tolerant quantum computation, a tight evaluation of the error threshold under practical noise models is essential. While non-Clifford noise is ubiquitous in experiments, the error threshold under non-Clifford noise cannot be...

A. Daskin, S. Kais·Mar 10, 2017

Abstract The eigenvalue of a Hamiltonian, H , can be estimated through the phase estimation algorithm given the matrix exponential of the Hamiltonian, exp ( - i H ) . The difficulty of this exponentiation impedes the applications of the phase estimat...

Zhi-Cheng Yang, A. Hamma, S. Giampaolo +2 more·Mar 9, 2017

Entanglement is usually quantified by von Neumann entropy, but its properties are much more complex than what can be expressed with a single number. We show that the three distinct dynamical phases known as thermalization, Anderson localization, and ...

Nayeli A. Rodríguez-Briones, Jun Yu Li, Xinhua Peng +3 more·Mar 8, 2017

Cooling techniques are essential to understand fundamental thermodynamic questions of the low-energy states of physical systems, furthermore they are at the core of practical applications of quantum information science. In quantum computing, this con...