Universal quantum computation with electronic qubits in decoherence-free subspace

2008 ◽  
Vol 8 (1&2) ◽  
pp. 96-105
Author(s):  
X.L. Zhang ◽  
M. Feng ◽  
K.L. Gao
Keyword(s):  
Quantum Information ◽  
Quantum Computation ◽  
Degrees Of Freedom ◽  
Quantum Information Processing ◽  
Building Blocks ◽  
Free Electrons ◽  
Single Spin ◽  
Universal Quantum ◽  
Phase Gate ◽  
Decoherence Free Subspace

We investigate how to carry out universal quantum computation deterministically with free electrons in decoherence-free subspace by using polarizing beam splitters, charge detectors, and single-spin rotations. Quantum information in our case is encoded in spin degrees of freedom of the electron-pairs which construct a decoherence-free subspace. We design building blocks for two noncommutable single-logic-qubit gates and a logic controlled phase gate, based on which a universal and scalable quantum information processing robust to dephasing is available in a deterministic way.

Universal quantum computation with quantum-dot cellular automata in decoherence-free subspace

2008 ◽  
Vol 8 (10) ◽  
pp. 977-985
Author(s):  
Z.-Y. Xu ◽  
M. Feng ◽  
W.-M. Zhang
Keyword(s):  
Cellular Automata ◽  
Quantum Dot ◽  
Quantum Computation ◽  
Two Dimensions ◽  
High Fidelity ◽  
Electron Pairs ◽  
Quantum Dot Cellular Automata ◽  
Single Spin ◽  
Universal Quantum ◽  
Decoherence Free Subspace

We investigate the possibility to have electron-pairs in decoherence-free subspace (DFS), by means of the quantum-dot cellular automata (QCA) and single-spin rotations, to deterministically carry out a universal quantum computation with high-fidelity. We show that our QCA device with electrons tunneling in two dimensions is very suitable for DFS encoding, and argue that our design favors a scalable quantum computation robust to collective dephasing errors.

EFFICIENT ALGORITHM FOR INITIALIZING AMPLITUDE DISTRIBUTION OF A QUANTUM REGISTER

2001 ◽  
Vol 15 (27) ◽  
pp. 1259-1264 ◽  
Author(s):  
M. ANDRECUT ◽  
M. K. ALI
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Computation ◽  
Quantum State ◽  
Efficient Algorithm ◽  
Quantum Information Processing ◽  
Amplitude Distribution ◽  
Quantum Register

The preparation of a quantum register in an arbitrary superposed quantum state is an important operation for quantum computation and quantum information processing. Here, we present an efficient algorithm which requires a polynomial number of elementary operations for initializing the amplitude distribution of a quantum register.

scholarly journals Engineering the quantum-classical interface of solid-state qubits

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
David J Reilly
Keyword(s):  
Quantum Information ◽  
Solid State ◽  
Degrees Of Freedom ◽  
Technology Development ◽  
Fault Tolerant ◽  
Building Blocks ◽  
Experimental Physicist ◽  
And Mathematics ◽  
Classical Control ◽  
And Control

AbstractSpanning a range of hardware platforms, the building-blocks of quantum processors are today sufficiently advanced to begin work on scaling-up these systems into complex quantum machines. A key subsystem of all quantum machinery is the interface between the isolated qubits that encode quantum information and the classical control and readout technology needed to operate them. As few-qubit devices are combined to construct larger, fault-tolerant quantum systems in the near future, the quantum-classical interface will pose new challenges that increasingly require approaches from the engineering disciplines in combination with continued fundamental advances in physics, materials and mathematics. This review describes the subsystems comprising the quantum-classical interface from the viewpoint of an engineer, experimental physicist or student wanting to enter the field of solid-state quantum information technology. The fundamental signalling operations of readout and control are reviewed for a variety of qubit platforms, including spin systems, superconducting implementations and future devices based on topological degrees-of-freedom. New engineering opportunities for technology development at the boundary between qubits and their control hardware are identified, transversing electronics to cryogenics.

Non-local universal gates generated within a resonant magnetic cavity

2018 ◽  
Vol 18 (13&14) ◽  
pp. 1081-1094
Author(s):  
Francisco Delgado
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Complex Dynamics ◽  
Time Dependent ◽  
Quantum Evolution ◽  
Basic Block ◽  
Precise Control ◽  
Universal Quantum ◽  
Set Up

Quantum Information is a quantum resource being advised as a useful tool to set up information processing. Despite physical components being considered are normally two-level systems, still the combination of some of them together with their entangling interactions (another key property in the quantum information processing) become in a complex dynamics needing be addressed and modeled under precise control to set programmed quantum processing tasks. Universal quantum gates are simple controlled evolutions resembling some classical computation gates. Despite their simple forms, not always become easy fit the quantum evolution to them. SU(2) decomposition is a mechanism to reduce the dynamics on SU(2) operations in composed quantum processing systems. It lets an easier control of evolution into the structure required by those gates by the adequate election of the basis for the computation grammar. In this arena, SU(2) decomposition has been studied under piecewise magnetic field pulses. Despite, it is completely applicable for time-dependent pulses, which are more affordable technologically, could be continuous and then possibly free of resonant effects. In this work, we combine the SU(2) reduction with linear and quadratic numerical approaches in the solving of time-dependent Schr\"odinger equation to model and to solve the controlled dynamics for two-qubits, the basic block for composite quantum systems being analyzed under the SU(2) reduction. A comparative benchmark of both approaches is presented together with some useful outcomes for the dynamics in the context of quantum information processing operations.

Quantum non-gaussianity from an indefnite causal order of Gaussian operations

2021 ◽  
Author(s):  
Seid Koudia ◽  
Abdelhakim Gharbi
Keyword(s):  
Quantum Information ◽  
Quantum Key Distribution ◽  
Degrees Of Freedom ◽  
Quantum Communication ◽  
Quantum Information Processing ◽  
Quantum Metrology ◽  
Causal Order ◽  
Gaussian States ◽  
Control Qubit ◽  
Non Gaussian

Quantum non-Gaussian states are considered a useful resource for many tasks in quantum information processing, from quantum metrology and quantum sensing to quantum communication and quantum key distribution. Another useful tool that is gaining attention is the newly constructed quantum switch. Its applications in many tasks in quantum information have been proved to outperform many existing schemes in quantum communication and quantum thermometry. In this contribution, we demonstrate this to be very useful for engineering highly non-Gaussian states from Gaussian operations whose order is controlled by degrees of freedom of a control qubit. The nonconvexity of the set of Gaussian states and the set of Gaussian operations guarantees the emergence of non-Gaussianity after post-selection on the control qubit deterministically, in contrast to existing protocols in the literature. The nonclassicality of the resulting states is discussed accordingly.

SCHEME FOR QUANTUM CLONING AND QUANTUM INFORMATION PROCESSING WITH TRAPPED IONS

2007 ◽  
Vol 21 (12) ◽  
pp. 729-735
Author(s):  
ZHI-MING ZHAN
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Vibrational Mode ◽  
Trapped Ions ◽  
Distinct Advantage ◽  
Quantum Cloning ◽  
Universal Quantum ◽  
Data Bus

In this paper, a scheme is presented to implement the 1→2 universal quantum cloning machine (UQCM) with trapped ions. In this way, we also show that quantum information can be directly transferred from one ion to another. The distinct advantage of the scheme lies in the fact that it does not use the vibrational mode as the data bus. The vibrational mode is only virtually excited, which makes our scheme insensitive to heating, provided the system remains in the Lamb–Dicke regime.

scholarly journals Universal quantum computation in a neutral-atom decoherence-free subspace

2007 ◽  
Vol 75 (3) ◽  
Author(s):  
E. Brion ◽  
L. H. Pedersen ◽  
K. Mølmer ◽  
S. Chutia ◽  
M. Saffman
Keyword(s):  
Quantum Computation ◽  
Neutral Atom ◽  
Universal Quantum ◽  
Decoherence Free Subspace

scholarly journals Molecular spin qudits for quantum algorithms

2018 ◽  
Vol 47 (2) ◽  
pp. 501-513 ◽  
Author(s):  
Eufemio Moreno-Pineda ◽  
Clément Godfrin ◽  
Franck Balestro ◽  
Wolfgang Wernsdorfer ◽  
Mario Ruben
Keyword(s):  
Quantum Information ◽  
First Generation ◽  
Quantum Information Processing ◽  
Quantum Algorithms ◽  
Quantum Algorithm ◽  
Building Blocks ◽  
Molecular Devices ◽  
Hardware Platform ◽  
Spin Qubit ◽  
Molecular Spin

Molecules are promising building blocks for Quantum information processing. Herein we describe how a molecular multilevel nuclear spin qubit (or qudit, where d = 4), known as TbPc2, showing all necessary requirements to perform as a molecular hardware platform with a first generation of molecular devices enabling even quantum algorithm operations.

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