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Operator controllability refers to the ability to implement an arbitrary unitary in SU(N) and is a prerequisite for universal quantum computing. Controllability tests can be used in the design of quantum devices to reduce the number of…

We propose a universal gate set for quantum computing with all-to-all connectivity and intrinsic robustness to bit-flip errors based on parity encoding. We show that logical controlled phase gate and $R_z$ rotations can be implemented in…

Quantum Physics · Physics 2022-11-03 Michael Fellner , Anette Messinger , Kilian Ender , Wolfgang Lechner

A universal set of quantum gates is constructed for the recently developed jump-error correcting quantum codes. These quantum codes are capable of correcting errors arising from the spontaneous decay of distinguishable qubits into…

Quantum Physics · Physics 2007-05-23 G. Alber , M. Mussinger , A. Delgado

We demonstrate the applicability of a universal gate set in the parity encoding, which is a dual to the standard gate model, by exploring several quantum gate algorithms such as the quantum Fourier transform and quantum addition. Embedding…

Quantum Physics · Physics 2022-11-03 Michael Fellner , Anette Messinger , Kilian Ender , Wolfgang Lechner

In this tutorial we review the basic building blocks of Quantum Information Processing with cold trapped atomic-ions. We mainly focus on methods to implement single-qubit rotations and two-qubit entangling gates, which form a universal set…

Quantum Physics · Physics 2015-05-28 Roee Ozeri

Quantum computation offers the potential to solve fundamental yet otherwise intractable problems across a range of active fields of research. Recently, universal quantum-logic gate sets - the building blocks for a quantum computer - have…

Upon entangling a spatial binary alternative of a photon with its polarization, one can use single photons to study arbitrary 2-qubit states. Sending the photon through a Mach-Zehnder interferometer, equipped with sets of wave plates that…

Quantum Physics · Physics 2009-11-07 Berthold-Georg Englert , Christian Kurtsiefer , Harald Weinfurter

Recent developments in qudit-based quantum computing, in particular with trapped ions, open interesting possibilities for scaling quantum processors without increasing the number of physical information carriers. In this work, we propose a…

Quantum Physics · Physics 2024-07-02 Anastasiia S. Nikolaeva , Evgeniy O. Kiktenko , Aleksey K. Fedorov

Multi-controlled unitary gates have been a subject of interest in quantum computing since its inception, and are widely used in quantum algorithms. The current state-of-the-art approach to implementing n-qubit multi-controlled gates…

We present a way to realize a multiplex-controlled phase gate of n-1 control qubits simultaneously controlling one target qubit, with n qubits distributed in n different cavities. This multiqubit gate is implemented by using n qutrits…

Quantum Physics · Physics 2019-10-21 Biaoliang Ye , Zhen-Fei Zheng , Chui-Ping Yang

We consider a two-qubit unitary operation along with arbitrary local unitary operations acts on a two-qubit pure state, whose entanglement is C_0. We give the conditions that the final state can be maximally entangled and be non-entangled.…

Quantum Physics · Physics 2009-11-10 M. -Y. Ye , Dong Sun , Y. -S. Zhang , G. -C. Guo

Quantum computation and quantum control operate by building unitary transformations out of sequences of elementary quantum logic operations or applications of control fields. This paper puts upper bounds on the minimum time required to…

Quantum Physics · Physics 2019-01-14 Seth Lloyd , Reevu Maity

We demonstrate that complete set of gates can be realized in a DXD superconducting solid state quantum computer (quamputer), thereby proving its universality.

Quantum Physics · Physics 2009-10-31 Alexandre Blais , Alexandre M. Zagoskin

Universal quantum computing requires the ability to perform every unitary operation, i.e., evolution operator controllability. In view of developing resource-efficient quantum processing units (QPUs), it is important to determine how many…

Quantum Physics · Physics 2026-02-18 Fernando Gago-Encinas , Christiane P. Koch

We propose a scheme for realizing quantum controlled phase gates with two nonidentical quantum dots trapped in two coupled photonic crystal cavities and driven by classical laser fields under the condition of non-small hopping limit. During…

Quantum Physics · Physics 2015-03-19 Jian-Qi Zhang , Ya-Fei Yu , Zhi-Ming Zhang

In the standard circuit model, elementary gates are defined relative to a chosen tensor factorization and are therefore extrinsic to the ambient group $U(2^n)$. Writing $N=2^n$, we introduce an \emph{intrinsic descriptor layer} in $U(N)$ by…

Quantum Physics · Physics 2026-03-03 Antonio Falco , Daniela Falco-Pomares , Hermann G. Matthies

We consider a mechanism to generate controllable qudit-qudit interactions in a charge-position paradigm for a quantum computer, through the use of auxiliary states. By controlling the tunneling rates onto these auxiliaries from the qudits…

Quantum Physics · Physics 2007-05-23 S. G. Schirmer , A. D. Greentree , D. K. L. Oi

We present a new implementation of quantum computation that treats quantum computers as a special type of Bayesian Network called a QuDot Net. QuDot Nets allow for the efficient representation of some qubit systems. Single qubit quantum…

Quantum Physics · Physics 2016-07-28 Perry Sakkaris

We prepare a gate-defined quadruple quantum dot to study the gate-tunability of single to quadruple quantum dots with finite inter-dot tunnel couplings. The measured charging energies of various double dots suggest that the dot size is…

Mesoscale and Nanoscale Physics · Physics 2014-03-21 Tatsuki Takakura , Akito Noiri , Toshiaki Obata , Tomohiro Otsuka , Jun Yoneda , Katsuharu Yoshida , Seigo Tarucha

Quantifying quantum states' complexity is a key problem in various subfields of science, from quantum computing to black-hole physics. We prove a prominent conjecture by Brown and Susskind about how random quantum circuits' complexity…