Papers

Z. Cai, S. Benjamin·Jul 13, 2018

Twirling is a technique widely used for converting arbitrary noise channels into Pauli channels in error threshold estimations of quantum error correction codes. It is vitally useful both in real experiments and in classical quantum simulations. Mini...

Akshaya Jayashankar, Prabha Mandayam·Jul 11, 2018

We examine the role of quantum error correction (QEC) in achieving pretty good quantum state transfer over a class of $1$-d spin Hamiltonians. Recasting the problem of state transfer as one of information transmission over an underlying quantum chann...

Theodoros Kapourniotis, A. Datta·Jul 11, 2018

We introduce the notion of fault-tolerant quantum metrology to overcome noise beyond our control, associated with sensing the parameter, by reducing the noise in operations under our control, associated with preparing and measuring probes and ancilla...

Q. Guo, Shi-Biao Zheng, Jianwen Wang +11 more·Jul 10, 2018

A central task towards building a practical quantum computer is to protect individual qubits from decoherence while retaining the ability to perform high-fidelity entangling gates involving arbitrary two qubits. Here we propose and demonstrate a deph...

Sam McArdle, Xiao Yuan, S. Benjamin·Jul 6, 2018

Variational algorithms may enable classically intractable simulations on near-future quantum computers. However, their potential is limited by hardware errors. It is therefore crucial to develop efficient ways to mitigate these errors. Here, we propo...

Sumeet Khatri, Ryan Larose, Alexander Poremba +3 more·Jul 2, 2018

Compiling quantum algorithms for near-term quantum computers (accounting for connectivity and native gate alphabets) is a major challenge that has received significant attention both by industry and academia. Avoiding the exponential overhead of clas...

Vishal Sharma, Subhashis Banerjee·Jul 1, 2018

Quantum key distribution is an effective encryption technique which can be used to perform secure quantum communication between satellite and ground stations. Quantum cryptography enhances security in various networks such as optical fibers and wirel...

Zhikuan Zhao, Alejandro Pozas-Kerstjens, P. Rebentrost +1 more·Jun 29, 2018

Bayesian methods in machine learning, such as Gaussian processes, have great advantages compared to other techniques. In particular, they provide estimates of the uncertainty associated with a prediction. Extending the Bayesian approach to deep archi...

C'edric B'eny, Z. Zimbor'as, F. Pastawski·Jun 27, 2018

Numerous quantum many-body systems are characterized by either fundamental or emergent constraints---such as gauge symmetries or parity superselection for fermions---which effectively limit the accessible observables and realizable operations. Moreov...

Yiğit Subaşı, L. Cincio, Patrick J. Coles·Jun 22, 2018

Noisy intermediate-scale quantum (NISQ) computers have gate errors and decoherence, limiting the depth of circuits that can be implemented on them. A strategy for NISQ algorithms is to reduce the circuit depth at the expense of increasing the qubit c...

L. Postler, Á. Rivas, P. Schindler +6 more·Jun 21, 2018

Correlations between different partitions of quantum systems play a central role in a variety of many-body quantum systems, and they have been studied exhaustively in experimental and theoretical research. Here, we investigate dynamical correlations ...

M. Otten, S. Gray·Jun 20, 2018

We introduce a technique for recovering noise-free observables in noisy quantum systems by combining the results of many slightly different experiments. Our approach is applicable to a variety of quantum systems but we illustrate it with applications...

Xuegang Li, Yuwei Ma, Jiaxiu Han +8 more·Jun 11, 2018

Faithfully transferring the quantum state is essential for quantum information processing. Here we demonstrate a fast (in 84 ns) and high-fidelity (99.2%) transfer of arbitrary quantum states in a chain of four superconducting qubits with nearest-nei...

Lihua Sun, Futian Liang, Jin Lin +4 more·Jun 10, 2018

Superconducting quantum computers (SQCs) can solve some specific problems which are deeply believed to be intractable for classical computers. One of the key components of SQCs is a high-precision synchronous control system which consists of arbitrar...

Futian Liang, P. Miao, Jin Lin +6 more·Jun 7, 2018

The Superconducting Quantum Computing (SQC) is one of the most promising quantum computing techniques. The SQC requires precise control and acquisition to operate the superconducting qubits. The ultra-precision DC source is used to provide a DC bias ...

Ieshan Vaidya·Jun 7, 2018

Quantum simulation presents itself as one of the biggest advantages of developing quantum computers. Simulating a quantum system classically is almost impossible beyond a certain system size whereas a controllable quantum system inherently has the re...

R. Harper, S. Flammia·Jun 6, 2018

Quantum computers will require encoding of quantum information to protect them from noise. Fault-tolerant quantum computing architectures illustrate how this might be done but have not yet shown a conclusive practical advantage. Here we demonstrate t...

Christina Knapp, M. Beverland, D. Pikulin +1 more·Jun 4, 2018

Majorana-based quantum computing seeks to use the non-local nature of Majorana zero modes to store and manipulate quantum information in a topologically protected way. While noise is anticipated to be significantly suppressed in such systems, finite ...

G. Nannicini·May 30, 2018

The recent literature on near-term applications for quantum computers contains several examples of the applications of hybrid quantum-classical variational approaches. This methodology can be applied to a variety of optimization problems, but its pra...

Guanru Feng, F. Cho, Hemant Katiyar +4 more·May 29, 2018

Quantum optimal control can play a crucial role to realize a set of universal quantum logic gates with error rates below the threshold required for fault-tolerance. Open-loop quantum optimal control relies on accurate modeling of the quantum system u...