Papers

D. Braun, R. Müller·Sep 16, 2021

Quantum algorithms profit from the interference of quantum states in an exponentially large Hilbert space and the fact that unitary transformations on that Hilbert space can be broken down to universal gates that act only on one or two qubits at the ...

C. Cortes, S. Gray·Sep 14, 2021

Quantum Krylov subspace diagonalization (QKSD) algorithms provide a low-cost alternative to the conventional quantum phase estimation algorithm for estimating the ground and excited-state energies of a quantum many-body system. While QKSD algorithms ...

P. Rakyta, Z. Zimbor'as·Sep 14, 2021

In this work we propose a novel numerical approach to decompose general quantum programs in terms of single- and two-qubit quantum gates with a CNOT gate count very close to the current theoretical lower bounds. In particular, it turns out that 15 an...

Agustín Borgna, S. Perdrix, Benoît Valiron·Sep 13, 2021

We present a complete optimization procedure for hybrid quantum-classical circuits with classical parity logic. While common optimization techniques for quantum algorithms focus on rewriting solely the pure quantum segments, there is interest in appl...

J. Herrmann, Sergi Masot Llima, A. Remm +15 more·Sep 13, 2021

Quantum computing crucially relies on the ability to efficiently characterize the quantum states output by quantum hardware. Conventional methods which probe these states through direct measurements and classically computed correlations become comput...

Ali Shaib, Mohamad H. Naim, M. Fouda +2 more·Sep 10, 2021

Quantum computers have enabled solving problems beyond the current machines’ capabilities. However, this requires handling noise arising from unwanted interactions in these systems. Several protocols have been proposed to address efficient and accura...

John R Scott, K. Balram·Sep 10, 2021

Most of the architectural research on photonic implementations of measurement-based quantum computing (MBQC) has focused on the quantum resources involved in the problem with the implicit assumption that these will provide the main constraints on sys...

Colton Griffin, Shawn X. Cui·Sep 10, 2021

We study a method of producing approximately diagonal 1-qubit gates. For each positive integer, the method provides a sequence of gates that are defined iteratively from a fixed diagonal gate and an arbitrary gate. These sequences are conjectured to ...

Ye‐Hong Chen, R. Stassi, W. Qin +2 more·Sep 10, 2021

We propose a theoretical protocol to implement multiqubit geometric gates (i.e., the M{\o}lmer-S{\o}rensen gate) using photonic cat-state qubits. These cat-state qubits stored in high-$Q$ resonators are promising for hardware-efficient universal quan...

B. Ruzic, T. Barrick, J. Hunker +7 more·Sep 9, 2021

Entangling gates in trapped-ion quantum computing have primarily targeted stationary ions with initial motional distributions that are thermal and close to the ground state. However, future systems will likely incur significant non-thermal excitation...

Sebastian Brandhofer, H. Büchler, I. Polian·Sep 9, 2021

Quantum algorithms promise quadratic or exponential speedups for applications in cryptography, chemistry and material sciences. The topologies of today's quantum computers offer limited connectivity, leading to significant overheads for implementing ...

Muhammad Ahsan·Sep 8, 2021

Crosstalk and several sources of operational interference are invisible when qubit or a gate is calibrated or benchmarked in isolation. These are unlocked during the execution of full quantum circuit applying entangling gates to several qubits simult...

Peihao Huang·Sep 6, 2021

A spin qubit in semiconductor quantum dots holds promise for quantum information processing for scalability and long coherence time. An important semiconductor qubit system is a double quantum dot trapping two electrons or holes, whose spin states en...

S. Ashhab, F. Yoshihara, T. Fuse +3 more·Sep 3, 2021

We consider the implementation of two-qubit gates when the physical systems used to realize the qubits possess additional quantum states in the accessible energy range. We use optimal control theory to determine the maximum achievable gate speed for ...

Jia-bin You, Dax Enshan Koh, J. Kong +3 more·Sep 1, 2021

Finding the ground state energy and wavefunction of a quantum many-body system is a key problem in quantum physics and chemistry. We study this problem for the long-range XY model by using the variational quantum eigensolver (VQE) algorithm. We consi...

T. Inada, Wonho Jang, Y. Iiyama +4 more·Aug 31, 2021

Quantum error correction is a crucial step beyond the current noisy-intermediate-scale quantum device towards fault-tolerant quantum computing. However, most of the error corrections ever demonstrated rely on post-selection of events or post-correcti...

W. Yan, Ying-Jie Zhang, Z. Man +2 more·Aug 30, 2021

Benefiting from the excellent control of single photons realized by the emitter-photon-chiral couplings, we propose a novel potential photonic-quantum-computation scheme to perform the supervised learning tasks. The gates for photonic quantum computat...

D. Kurkcuoglu, M. S. Alam, Joshua Job +4 more·Aug 30, 2021

We discuss the implementation of quantum algorithms for lattice $\Phi^4$ theory on circuit quantum electrodynamics (cQED) system. The field is represented on qudits in a discretized field amplitude basis. The main advantage of qudit systems is that i...

G. Cui, Zhimin Wang, Shengbin Wang +5 more·Aug 27, 2021

Solving differential equations is one of the most promising applications of quantum computing. Recently we proposed an efficient quantum algorithm for solving one-dimensional Poisson equation avoiding the need to perform quantum arithmetic or Hamilto...

K. Sahay, Benjamin J. Brown·Aug 25, 2021

The color code is remarkable for its ability to perform fault-tolerant logic gates. This motivates the design of practical decoders that minimise the resource cost of color-code quantum computation. Here we propose a decoder for the planar color code...