Floquet-engineering counterdiabatic protocols in quantum many-body systems

Counterdiabatic (CD) driving presents a way of generating adiabatic dynamics at arbitrary pace, where excitations due to non-adiabaticity are exactly compensated by adding an auxiliary driving term to the Hamiltonian. While this CD term is theoretically known and given by the adiabatic gauge potential, obtaining and implementing this potential in many-body systems is a formidable task, requiring knowledge of the spectral properties of the instantaneous Hamiltonians and control of highly nonlocal multibody interactions. We show how an approximate gauge potential can be systematically built up as a series of nested commutators, remaining well-defined in the thermodynamic limit. Furthermore, the resulting CD driving protocols can be realized up to arbitrary order without leaving the available control space using tools from periodically-driven (Floquet) systems. This is illustrated on few- and many-body quantum systems, where the resulting Floquet protocols significantly suppress dissipation and provide a drastic increase in fidelity.Comment: 6+3 page

Heritability estimates of the novel trait 'suppressed in ovo virus infection' in honey bees (Apis mellifera)

Honey bees are under pressure due to abnormal high colony death rates, especially during the winter. The infestation by the Varroa destructor mite and the viruses that this ectoparasite transmits are generally considered as the bees' most important biological threats. Almost all efforts to remedy this dual infection have so far focused on the control of the Varroa mite alone and not on the viruses it transmits. In the present study, the sanitary control of breeding queens was conducted on eggs taken from drone brood for 4 consecutive years (2015-2018). The screening was performed on the sideline of an ongoing breeding program, which allowed us to estimate the heritabilities of the virus status of the eggs. We used the term 'suppressed in ovo virus infection' (SOV) for this novel trait and found moderate heritabilities for the presence of several viruses simultaneously and for the presence of single viral species. Colonies that expressed the SOV trait seemed to be more resilient to virus infections as a whole with fewer and less severe Deformed wing virus infections in most developmental stages, especially in the male caste. The implementation of this novel trait into breeding programs is recommended

Large gap asymptotics at the hard edge for product random matrices and Muttalib-Borodin ensembles

We study the distribution of the smallest eigenvalue for certain classes of positive-definite Hermitian random matrices, in the limit where the size of the matrices becomes large. Their limit distributions can be expressed as Fredholm determinants of integral operators associated to kernels built out of Meijer G-functions or Wright's generalized Bessel functions. They generalize in a natural way the hard edge Bessel kernel Fredholm determinant. We express the logarithmic derivatives of the Fredholm determinants identically in terms of a 2×2 Riemann-Hilbert problem, and use this representation to obtain the so-called large gap asymptotics

Large gap asymptotics at the hard edge for product random matrices and Muttalib-Borodin ensembles

We study the distribution of the smallest eigenvalue for certain classes of positive-definite Hermitian random matrices, in the limit where the size of the matrices becomes large. Their limit distributions can be expressed as Fredholm determinants of integral operators associated to kernels built out of Meijer G-functions or Wright's generalized Bessel functions. They generalize in a natural way the hard edge Bessel kernel Fredholm determinant. We express the logarithmic derivatives of the Fredholm determinants identically in terms of a 2×2 Riemann-Hilbert problem, and use this representation to obtain the so-called large gap asymptotics

The Importance of the Great War Compared to Long-term Developments in Restructuring the Rural Landscape in Flanders (Belgium)

status: Published onlin

Removing the Spectral Leakage in Time-Domain Based Near-Field Scanning Measurements

This paper describes the application of a new and easy to implement algorithm to EMI near-field scanning measurement results obtained with a time-domain-based measurement system. The algorithm aims to reduce the effect of spectral leakage on amplitude and phase of the measured field components. The proposed algorithm significantly increases the accuracy of the measured electromagnetic near field with a limited extra computational cost. The versatility and effectiveness of the proposed algorithm is shown on both simulated and measured data. It is shown that for situations with one single frequency component or with several well-separated frequency components, the algorithm is as performant as the application of a flat top window and outperforms other types of windows. However, as soon as the frequency components approach each other implying their spectral leakage patterns overlap, the proposed algorithm outperforms the application of a flat top window.status: publishe

Simulated-annealing algorithm to solve multi-component matching problems in generalised selective assembly

Generalized Selective Assembly is a strategy of intelligently matching components based on their measured feature values. This strategy requires algorithms that, given a list of components, their measured feature values, and a list of quality constraints between the components, returns a list of assemblies and their comprising components, maximizing the number of in-spec assemblies. Although assemblies in practice often involve one-to-many, many-to-one or many-to-many constraints, most algorithms reported in literature involve one-to-one constraints. Therefore, in this paper a Simulated Annealing algorithm is developed that involves these types of constraints and that is able to solve the problem fast enough to be practical in manufacturing environments. The developed Simulated Annealing algorithm outperforms other heuristic approaches proposed in literature by finding consistently more in-spec assemblies in the same running time

Influence of Sample Shape and Size on the Shielding Effectiveness of EMI when Characterized with the Stripline Test Method

This paper studies the influence of a gasket’s shape and size on its high-frequency shielding-effectiveness as measured with the stripline test method. Based on full-wave simulations it is shown that the main influencing parameter for the shielding-effectiveness is the gasket’s conductivity. Through a comparison with the reverberation room method, it is shown that differences due to shape and size of the gasket are not related to the stripline set-up, but are a reflection of the true shielding effectiveness of the gasket.status: publishe