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We introduce a method to suppress unwanted transition channels, even without knowing their couplings, and achieve perfect population transfer in multistate quantum systems by the application of composite pulse sequences. Unwanted transition…

Quantum Physics · Physics 2015-06-11 Genko T. Genov , Nikolay V. Vitanov

Nonlinear effects are the root of interesting phenomena such as masers and lasers, and play a significant role in science and engineering. In spin systems, nonlinear spin dynamics is crucial for the prediction of complex dynamical behavior…

Quantum Gases · Physics 2024-10-23 Tishuo Wang , Zhihuang Luo , Shizhong Zhang , Zhenhua Yu

Radio waves propagating from distant pulsars in the interstellar medium (ISM), are refracted by electron density inhomogeneities, so that the intensity of observed pulses fluctuates with time. The theory relating the observed pulse…

Astrophysics · Physics 2009-11-10 Stanislav Boldyrev , Carl R. Gwinn

Achieving high-fidelity control of quantum systems is essential for realization of a practical quantum computer. Composite pulse sequences which suppress different types of errors can be nested to suppress a wide variety of errors but the…

Mesoscale and Nanoscale Physics · Physics 2019-12-09 Utkan Güngördü , J. P. Kestner

For the implementation of a quantum computer it is necessary to exercise complete control over the Hamiltonian of the used physical system. For NMR quantum computing the effectively acting Hamiltonian can be manipulated via pulse sequences.…

Quantum Physics · Physics 2009-11-07 Marcus Stollsteimer , Guenter Mahler

Composite Pulses (CPs) are widely used in Nuclear Magnetic Resonance (NMR), optical spectroscopy, optimal control experiments and quantum computing to manipulate systems that are well-described by a two-level Hamiltonian. A careful design…

Quantum Physics · Physics 2025-07-03 Jonathan Berkheim , David J. Tannor

We consider the NMR signal from a permeable medium with a heterogeneous Larmor frequency component that varies on a scale comparable to the spin-carrier diffusion length. We focus on the mesoscopic part of the transverse relaxation, that…

Mesoscale and Nanoscale Physics · Physics 2008-10-23 D. S. Novikov , V. G. Kiselev

We study the spectral representation and dispersion relations that follow from some basic assumptions and the reduced spacetime symmetries on noncommutative (NC) space. Kinematic variables involving the NC parameter appear naturally as…

High Energy Physics - Theory · Physics 2009-11-07 Yi Liao , Klaus Sibold

We study the functional relationship between quantum control pulses in the idealized case and the pulses in the presence of an unwanted drift. We show that a class of artificial neural networks called LSTM is able to model this functional…

Quantum Physics · Physics 2022-08-30 M. Ostaszewski , J. A. Miszczak , P. Sadowski , L. Banchi

Composite system is studied in noncommutative phase space with preserved rotational symmetry. We find conditions on the parameters of noncommutativity on which commutation relations for coordinates and momenta of the center-of-mass of…

Quantum Physics · Physics 2018-02-27 Kh. P. Gnatenko , V. M. Tkachuk

We study the effect of noncommutativity of space on the physics of a quantum interferometer located in a rotating disk in a gauge field background. To this end, we develop a path-integral approach which allows defining an effective action…

High Energy Physics - Theory · Physics 2010-11-19 H. R. Christiansen , F. A. Schaposnik

We develop a non-linear framework for describing long-wavelength perturbations in multiple-field inflation. The basic variables describing inhomogeneities are defined in a non-perturbative manner, are invariant under changes of time slicing…

Astrophysics · Physics 2009-11-11 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

Dense spin ensembles in solids present a natural platform for studying quantum many-body dynamics. Multiple-pulse coherent control can be used to manipulate the magnetic dipolar interaction between the spins to engineer their dynamics.…

Quantum Physics · Physics 2024-12-24 Linta Joseph , Wynter Alford , Chandrasekhar Ramanathan

We describe novel composite pulse sequences which act as general rotors and thus are suitable for nuclear magnetic resonance (NMR) quantum computation. The Resonance Offset Tailoring To Enhance Nutations (ROTTEN) approach permits perfect…

Quantum Physics · Physics 2007-05-23 H. K. Cummins , J. A. Jones

We study the distribution of non-overlapping spacing ratios of higher-orders for complex interacting many-body quantum systems, with and without spin degree of freedom (in addition to the particle number). The Hamiltonian of such systems is…

Statistical Mechanics · Physics 2019-12-13 Priyanka Rao , Manan Vyas , N. D. Chavda

Modified dispersion relations (MDRs) and noncommutative geometries are phenomenological models of Planck-scale corrections to relativistic kinematics, motivated by several approaches to quantum gravity. High-energy astrophysical…

High Energy Physics - Theory · Physics 2024-12-24 Pasquale Bosso , Fabrizio Illuminati , Luciano Petruzziello , Fabian Wagner

In the previous paper [arXiv:2210.10435], the nonlinear perturbation theory of cosmological density field is generalized to include the tensor-valued bias of astronomical objects, such as spins and shapes of galaxies and any other tensors…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-23 Takahiko Matsubara

We calculate the plasmon dispersion in quasi-one-dimensional quantum wires, in the presence of non-magnetic impurities, taking into consideration the memory function formalism and the role of the forward scattering. The plasma frequency is…

Disordered Systems and Neural Networks · Physics 2009-11-13 I. Grosu , L. Tugulan

The discrete Uehling-Uhlenbeck equations are solved to study the propagation of plane (sound) waves in a system of composite fermionic particles with hard-sphere interactions and the filling factor ($\nu$) being 1/2. The Uehling-Uhlenbeck…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. Kwang-Hua Chu

We develop a systematic approach to derive narrowband (NB) and passband (PB) composite sequences which can produce any pre-selected transition probability with any desired accuracy. The NB composite pulses are derived by successive…

Quantum Physics · Physics 2020-07-15 Boyan T. Torosov , Svetoslav S. Ivanov , Nikolay V. Vitanov