English
Related papers

Related papers: The quantum computational speed of a single Cooper…

200 papers

Non-classical features of quantum systems can degrade when subjected to environment and noise. Here, we ask a fundamental question: What is the minimum amount of time it takes for a quantum system to exhibit non-classical features in the…

Quantum Physics · Physics 2024-09-23 Divyansh Shrimali , Swapnil Bhowmick , Arun Kumar Pati

We introduce the concept of strong quantum speedup. We prove that approximating the ground state energy of an instance of the time-independent Schr\"odinger equation, with $d$ degrees of freedom, $d$ large, enjoys strong exponential quantum…

Quantum Physics · Physics 2013-09-04 Anargyros Papageorgiou , Joseph F. Traub

The energy gap is calculated for the ground state quantum computer circuit, which was recently proposed by Mizel et.al. When implementing a quantum algorithm by Hamiltonians containing only pairwise interaction, the inverse of energy gap…

Quantum Physics · Physics 2009-11-10 Wenjin Mao

Image processing is a fascinating field for exploring quantum algorithms. However, achieving quantum speedups turns out to be a significant challenge. In this work, we focus on image filtering to identify a class of images that can achieve…

Quantum Physics · Physics 2023-08-01 Zidong Cui , Shan Jin , Akira Sone , Xiaoting Wang

The single photon occupation of a localized field mode within an engineered network of defects in a photonic band-gap (PBG) material is proposed as a unit of quantum information (qubit). Qubit operations are mediated by optically-excited…

Quantum Physics · Physics 2007-05-23 Nipun Vats , Terry Rudolph , Sajeev John

Quantum computer versus quantum algorithm processor in CMOS are compared to find (in parallel) all Hamiltonian cycles in a graph with m edges and n vertices, each represented by k bits. A quantum computer uses quantum states analogous to…

Hardware Architecture · Computer Science 2007-05-23 John Robert Burger

We explain the mechanism of the quantum speed-up - quantum algorithms requiring fewer computation steps than their classical equivalent - for a family of algorithms. Bob chooses a function and gives to Alice the black box that computes it.…

Quantum Physics · Physics 2015-05-27 Giuseppe Castagnoli

Quantum computing is a growing field where the information is processed by two-levels quantum states known as qubits. Current physical realizations of qubits require a careful calibration, composed by different experiments, due to noise and…

Quantum Physics · Physics 2023-09-15 Edoardo Pedicillo , Andrea Pasquale , Stefano Carrazza

The effect of the inevitable coupling to external degrees of freedom of a quantum computer are examined. It is found that for quantum calculations (in which the maintenance of coherence over a large number of states is important), not only…

High Energy Physics - Theory · Physics 2009-10-28 W. G. Unruh

Quantum algorithms are known for providing more efficient solutions to certain computational tasks than any corresponding classical algorithm. Here we show that a single qudit is sufficient to implement an oracle based quantum algorithm,…

Quantum speed limit is bound on the minimum time a quantum system requires to evolve from an initial state to final state under a given dynamical process. It sheds light on how fast a desired state transformation can take place which is…

Quantum Physics · Physics 2023-05-31 Vivek Pandey , Divyansh Shrimali , Brij Mohan , Siddhartha Das , Arun Kumar Pati

We show that the group velocity of a probe pulse in an ensemble of $\Lambda$-type atoms driven by a quantized cavity mode depends on the quantum state of the input probe pulse. In the strong-coupling regime of the atom-cavity system the…

Quantum Physics · Physics 2015-05-14 Gor Nikoghosyan , Michael Fleischhauer

Classification is at the core of data-driven prediction and decision-making, representing a fundamental task in supervised machine learning. Recently, several quantum machine learning algorithms that use quantum kernels as a measure of…

Quantum Physics · Physics 2024-08-12 Jungyun Lee , Daniel K. Park

In former work, we showed that a quantum algorithm requires the number of operations (oracle's queries) of a classical algorithm that knows in advance 50% of the information that specifies the solution of the problem. We gave a preliminary…

Quantum Physics · Physics 2010-04-07 Giuseppe Castagnoli

In this contribution, we study a single Cooper pair box interacts with a single cavity mode. We show the roles played by the detuning parameters and charged capacities on the degree of entanglement. For large values of the detuning…

Quantum Physics · Physics 2009-11-13 N. Metwally , A. A. El-Amin

We cast observable measure of quantum coherence or asymmetry as a resource to control the quantum speed limit (QSL) for unitary evolutions. For non-unitary evolutions, QSL depends on that of the state of the system and environment together.…

Quantum Physics · Physics 2016-02-17 Debasis Mondal , Chandan Datta , Sk Sazim

We show that quantum computation circuits using coherent states as the logical qubits can be constructed from simple linear networks, conditional photon measurements and "small" coherent superposition resource states.

Quantum Physics · Physics 2009-11-10 T. C. Ralph , A. Gilchrist , G. J. Milburn , W. J. Munro , S. Glancy

We propose an efficient approach for deterministically generating scalable cluster states with photons. This approach involves unitary transformations performed on atoms coupled to optical cavities. Its operation cost scales linearly with…

Quantum Physics · Physics 2010-05-28 Hefeng Wang , Chui-Ping Yang , Franco Nori

Developing a quantum light source that carries more than one bit per photon is pivotal for expanding quantum information applications. Characterizing a high-dimensional multiple-degree-of-freedom source at the single-photon level is…

Quantum Physics · Physics 2025-05-09 Dong Beom Kim , Xiye Hu , Alfred B. U'Ren , Karina Garay-Palmett , Virginia O. Lorenz

We analyze the problem of increasing the efficiency of single-photon sources or single-rail photonic qubits via linear optical processing and destructive conditional measurements. In contrast to previous work we allow for the use of…

Quantum Physics · Physics 2015-06-26 Dominic W. Berry , A. I. Lvovsky , Barry C. Sanders