Papers

Gengyan Zhang, Yanbing Liu, J. Raftery +1 more·Mar 3, 2016

We demonstrate the suppression of photon shot noise dephasing in a superconducting qubit by eliminating its dispersive coupling to the readout cavity. This is achieved in a tunable coupling qubit, where the qubit frequency and coupling rate can be co...

R. Patel, Joseph Ho, F. Ferreyrol +2 more·Mar 1, 2016

A quantum controlled-SWAP gate is demonstrated and used to implement small-scale algorithms and produce high-fidelity GHZ states. Minimizing the resources required to build logic gates into useful processing circuits is key to realizing quantum compu...

C. Branciard·Feb 29, 2016

It was recently realised that quantum theory allows for so-called causally nonseparable processes, which are incompatible with any definite causal order. This was first suggested on a rather abstract level by the formalism of process matrices, an ext...

R. Chapman, M. Santandrea, Zixin Huang +5 more·Feb 29, 2016

The transfer of data is a fundamental task in information systems. Microprocessors contain dedicated data buses that transmit bits across different locations and implement sophisticated routing protocols. Transferring quantum information with high fi...

Hao Zhang, Haibo Wang·Feb 29, 2016

In recent years, superconducting qubits show great potential in quantum computation. Hence, microwave photons become very interesting qubits for quantum information processing assisted by superconducting quantum computation. Here, we present the firs...

T. Morimae·Feb 28, 2016

We show that the class QAM does not change even if the verifier's ability is restricted to only single-qubit measurements. To show the result, we use the idea of the measurement-based quantum computing: the verifier, who can do only single-qubit meas...

K. Fujii, K. Nakajima·Feb 26, 2016

Quantum computer has an amazing potential of fast information processing. However, realisation of a digital quantum computer is still a challenging problem requiring highly accurate controls and key application strategies. Here we propose a novel pla...

D. Goyeneche, J. Bielawski, K. Życzkowski·Feb 25, 2016

Heterogeneous bipartite quantum pure states, composed of two subsystems with a different number of levels, cannot have both reductions maximally mixed. In this work, we demonstrate existence of a wide range of highly entangled states of heterogeneous...

K. Takeda, J. Kamioka, T. Otsuka +8 more·Feb 25, 2016

This is the first experimental demonstration of a fault-tolerant spin qubit in industry-compatible isotopically natural silicon. Fault-tolerant quantum computing requires high-fidelity qubits. This has been achieved in various solid-state systems, in...

Qi-Ping Su, Tongqi Liu, Chuiping Yang·Feb 24, 2016

The transfer of quantum entanglement (or quantum coherence) is not only fundamental in quantum mechanics but also important in quantum information processing. We here propose a way to achieve the coherent transfer of W-class entangled states of qubit...

Thomas Unden, P. Balasubramanian, Daniel Louzon +12 more·Feb 23, 2016

We experimentally demonstrate the protection of a room-temperature hybrid spin register against environmental decoherence by performing repeated quantum error correction whilst maintaining sensitivity to signal fields. We use a long-lived nuclear spi...

J. Casanova, Zhen-Yu Wang, M. Plenio·Feb 22, 2016

Selective control of qubits in a quantum register for the purposes of quantum information processing represents a critical challenge for dense spin ensembles in solid-state systems. Here we present a protocol that achieves a complete set of selective...

Xu-Chen Yang, Xin Wang·Feb 18, 2016

Semiconductor quantum dot spin qubits are promising candidates for quantum computing. In these systems, the dynamically corrected gates offer considerable reduction of gate errors and are therefore of great interest both theoretically and experimenta...

N. Cisternas, G. Araneda, O. Jim'enez +1 more·Feb 18, 2016

Recently, the nonlocal optimal probabilistic cloning (NLOPC) of two non-orthogonal qubit states has been proposed [Phys. Rev. A 86, 052332 (2012)] by means of an experimental setup based on a pair of twin photons in a maximally entangled state. Here ...

H. Homulle, Stefan Visser, B. Patra +4 more·Feb 18, 2016

The implementation of a classical control infrastructure for large-scale quantum computers is challenging due to the need for integration and processing time, which is constrained by coherence time. We propose a cryogenic reconfigurable platform as t...

S. Schwarz, A. Stefanov, S. Wolf +1 more·Feb 17, 2016

A problem in quantum information theory is to find the experimental setup that maximizes the nonlocality of correlations with respect to some suitable measure such as the violation of Bell inequalities. The latter has however some drawbacks. First an...

Lin Chen, D. Ðokovic·Feb 17, 2016

We investigate the separable states ρ of an arbitrary multi-partite quantum system with Hilbert space H of dimension d. The length L(ρ) of ρ is defined as the smallest number of pure product states having ρ as their mixture. The length filtration of ...

M. Gonzalez-Zalba, S. Shevchenko, S. Barraud +5 more·Feb 16, 2016

Quantum mechanical effects induced by the miniaturization of complementary metal-oxide-semiconductor (CMOS) technology hamper the performance and scalability prospects of field-effect transistors. However, those quantum effects, such as tunneling and...

Ben Freivogel, R. Jefferson, L. Kabir·Feb 15, 2016

A puzzling aspect of the AdS/CFT correspondence is that a single bulk operator can be mapped to multiple different boundary operators, or precursors. By improving upon a recent model of Mintun, Polchinski, and Rosenhaus, we demonstrate explicitly how...

N. Ofek, A. Petrenko, R. Heeres +10 more·Feb 15, 2016

The remarkable discovery of Quantum Error Correction (QEC), which can overcome the errors experienced by a bit of quantum information (qubit), was a critical advance that gives hope for eventually realizing practical quantum computers. In principle, ...