Papers

Tiago Debarba, F. Fanchini·Dec 14, 2016

Calculating the degree of non-Markovianity of a dissipative process is a difficult task, even for the dynamics of a single qubit, given the complex maximization problem. In this work, focusing on the entanglement-based quantifier of non-Markovianity,...

D. Greenbaum, Z. Dutton·Dec 12, 2016

Analysis of quantum error correcting codes is typically done using a stochastic, Pauli channel error model for describing the noise on physical qubits. However, it was recently found that coherent errors (systematic rotations) on physical data qubits...

Wojciech Słomczyński, Anna Szczepanek·Dec 11, 2016

We introduce two information-theoretical invariants for the projective unitary group acting on a finite-dimensional complex Hilbert space: PVM- and POVM-dynamical (quantum) entropies, which are analogues of the classical Kolmogorov-Sinai entropy rate...

C. Chamberland, Joel J. Wallman, Stefanie J. Beale +1 more·Dec 8, 2016

Quantum error correction is instrumental in protecting quantum systems from noise in quantum computing and communication settings. Pauli channels can be efficiently simulated and threshold values for Pauli error rates under a variety of error-correct...

F. Lecocq, L. Ranzani, G. Peterson +4 more·Dec 5, 2016

We report on the design and implementation of a field-programmable Josephson amplifier (FPJA)-a compact and lossless superconducting circuit that can be programmed in situ by a set of microwave drives to perform reciprocal and nonreciprocal frequency...

Wei Zhang, Daowen Qiu·Dec 3, 2016

Semi-quantum key distribution (SQKD) can share secret keys by using less quantum resource than its fully quantum counterparts, and this likely makes SQKD become more practical and realizable. In this paper, we present a new SQKD protocol by introduci...

D. McKay, C. J. Wood, S. Sheldon +2 more·Dec 2, 2016

For superconducting qubits, microwave pulses drive rotations around the Bloch sphere. The phase of these drives can be used to generate zero-duration arbitrary virtual $Z$ gates, which, combined with two ${X}_{\ensuremath{\pi}/2}$ gates, can generate...

J. Ghosh, S. Coppersmith, M. Friesen·Dec 2, 2016

Many realizations of solid-state qubits involve couplings to leakage states lying outside the computational subspace, posing a threat to high-fidelity quantum gate operations. Mitigating leakage errors is especially challenging when the coupling stre...

Mathias Soeken, M. Rötteler, N. Wiebe +1 more·Dec 2, 2016

A major hurdle to the deployment of quantum linear systems algorithms and recent quantum simulation algorithms lies in the difficulty to find inexpensive reversible circuits for arithmetic using existing hand coded methods. Motivated by recent advanc...

F. Pastawski, J. Preskill·Nov 30, 2016

Almheiri, Dong, and Harlow [arXiv:1411.7041] proposed a highly illuminating connection between the AdS/CFT holographic correspondence and operator algebra quantum error correction (OAQEC). Here we explore this connection further. We derive some gener...

B. Vermersch, P. Guimond, H. Pichler +1 more·Nov 30, 2016

We describe a quantum state transfer protocol, where a quantum state of photons stored in a first cavity can be faithfully transferred to a second distant cavity via an infinite 1D waveguide, while being immune to arbitrary noise (e.g., thermal noise...

Y. Matsuzaki, S. Benjamin·Nov 30, 2016

A solid state spin is an attractive system with which to realize an ultra-sensitive magnetic field sensor. A spin superposition state will acquire a phase induced by the target field, and we can estimate the field strength from this phase. Recent stu...

Haonan Xiong, Wentao Jiang, Yipu Song +1 more·Nov 28, 2016

The few-layer graphene quantum dot provides a promising platform for quantum computing with both spin and valley degrees of freedom. Gate-defined quantum dots in particular can avoid noise from edge disorders. In connection with the recent experiment...

J. Braumüller, M. Marthaler, A. Schneider +4 more·Nov 25, 2016

The quantum Rabi model describes the fundamental mechanism of light-matter interaction. It consists of a two-level atom or qubit coupled to a quantized harmonic mode via a transversal interaction. In the weak coupling regime, it reduces to the well-k...

D. G. Olivares, B. Peropadre, J. Huh +1 more·Nov 24, 2016

In this work, we propose a flexible architecture of microwave resonators with tuneable couplings to perform quantum simulations of molecular chemistry problems. The architecture builds on the experience of the D-Wave design, working with nearly harmo...

N. Chancellor, A. Kissinger, S. Zohren +2 more·Nov 23, 2016

We introduce a high-level graphical framework for designing and analysing quantum error correcting codes, centred on what we term the coherent parity check (CPC). The graphical formulation is based on the diagrammatic tools of the ZX-calculus of quan...

Asif Shakeel·Nov 22, 2016

History dependent discrete time quantum walks (QWs) are often studied for their lattice traversal properties. A particular model in the literature uses the state of a memory qubit at each site to record visits and to control the dynamics of the walk....

F. Pastawski, J. Eisert, H. Wilming·Nov 22, 2016

While originally motivated by quantum computation, quantum error correction (QEC) is currently providing valuable insights into many-body quantum physics, such as topological phases of matter. Furthermore, mounting evidence originating from holograph...

Neill Lambert, Y. Matsuzaki, K. Kakuyanagi +3 more·Nov 21, 2016

Superconducting flux qubits are a promising candidate for realizing quantum information processing and quantum simulations. Such devices behave like artificial atoms, with the advantage that one can easily tune the ``atoms'' internal properties. Here...

Tongqi Liu, Yang Zhang, Bao-qing Guo +2 more·Nov 21, 2016

The realization of cross-Kerr nonlinearity is an important task for many applications in quantum information processing. In this work, we propose a method for realizing cross-Kerr nonlinearity interaction between two superconducting coplanar waveguid...