Collective neutrino oscillations on a quantum computer with hybrid quantum-classical algorithm

We simulate the time evolution of collective neutrino oscillations in two-flavor settings on a quantum computer. We explore the generalization of Trotter-Suzuki approximation to time-dependent Hamiltonian dynamics. The trotterization steps are further optimized using the Cartan decomposition of two-qubit unitary gates U $\in$ SU (4) in the minimum number of controlled-NOT (CNOT) gates making the algorithm more resilient to the hardware noise. A more efficient hybrid quantum-classical algorithm is also explored to solve the problem on noisy intermediate-scale quantum (NISQ) devices.Comment: 9 pages, 10 figure

Symmetry breaking/symmetry preserving circuits and symmetry restoration on quantum computers: A quantum many-body perspective

We discuss here some aspects related to symmetries of a quantum many-body problem when trying to treat it on a quantum computer. Several features related to symmetry conservation, symmetry breaking and possible symmetry restoration are reviewed. After a brief discussion of some of the standard symmetries relevant for many-particle systems, we discuss the advantage to encode directly some symmetries in quantum ansatze, especially with the aim to reduce the quantum register size. It is however well-known that the use of symmetry breaking states can also be a unique way to incorporate specific internal correlations when a spontaneous symmetry breaking occurs. These aspects are discussed in the quantum computing context. Precise description of quantum systems can however be achieved only when the symmetries that are initially broken are properly restored. Several methods are introduced to perform symmetry restoration on a quantum computer, for instance, purification of the state by means of the Grover algorithm, use of the combination of Hadamard test and oracle concepts, symmetry filtering by quantum phase estimation and by an iterative independent set of Hadamard tests.Comment: submitted to Eur. Phys. J. A in the topical issue on "Quantum computing in low-energy nuclear theory

Quantum information and quantum simulation of neutrino physics

In extreme astrophysical environments such as core-collapse supernovae and binary neutron star mergers, neutrinos play a major role in driving various dynamical and microphysical phenomena, such as baryonic matter outflows, the synthesis of heavy elements, and the supernova explosion mechanism itself. The interactions of neutrinos with matter in these environments are flavor-specific, which makes it of paramount importance to understand the flavor evolution of neutrinos. Flavor evolution in these environments can be a highly nontrivial problem thanks to a multitude of collective effects in flavor space, arising due to neutrino-neutrino ($\nu$-$\nu$) interactions in regions with high neutrino densities. A neutrino ensemble undergoing flavor oscillations under the influence of significant $\nu$-$\nu$ interactions is somewhat analogous to a system of coupled spins with long-range interactions among themselves and with an external field ('long-range' in momentum-space in the case of neutrinos). As a result, it becomes pertinent to consider whether these interactions can give rise to significant quantum correlations among the interacting neutrinos, and whether these correlations have any consequences for the flavor evolution of the ensemble. In particular, one may seek to utilize concepts and tools from quantum information science and quantum computing to deepen our understanding of these phenomena. In this article, we attempt to summarize recent work in this field. Furthermore, we also present some new results in a three-flavor setting, considering complex initial states.Comment: 13 pages, 3 figures. Invited review for the Eur. Phys. J. A special issue on "Quantum computing in low-energy nuclear theory

Filtering states with total spin on a quantum computer

International audienceStarting from a general wave-function described on a set of spins or qubits, we propose several quantum algorithms to extract the components of this state on eigenstates of total spin S2 and its z component Sz. The method plays the role of total spin projection and gives access to the amplitudes of the initial state on a total spin basis. The different algorithms have various degrees of sophistication depending on the requested tasks. They can either solely project onto the subspace with good total spin or completely uplift the degeneracy in this subspace. In the former case, when the projection on the total spin j is made, we show that the number of operations for the projection can be reduced from a quadratic to a linear dependence in j. After each measurement, the state collapses to one of the spin eigenstates that could be used for postprocessing. For this reason, we call the method total quantum spin filtering

Symmetry breaking/symmetry preserving circuits and symmetry restoration on quantum computers: A quantum many-body perspective

We discuss here some aspects related to symmetries of a quantum many-body problem when trying to treat it on a quantum computer. Several features related to symmetry conservation, symmetry breaking and possible symmetry restoration are reviewed. After a brief discussion of some of the standard symmetries relevant for many-particle systems, we discuss the advantage to encode directly some symmetries in quantum ansatze, especially with the aim to reduce the quantum register size. It is however well-known that the use of symmetry breaking states can also be a unique way to incorporate specific internal correlations when a spontaneous symmetry breaking occurs. These aspects are discussed in the quantum computing context. Precise description of quantum systems can however be achieved only when the symmetries that are initially broken are properly restored. Several methods are introduced to perform symmetry restoration on a quantum computer, for instance, purification of the state by means of the Grover algorithm, use of the combination of Hadamard test and oracle concepts, symmetry filtering by quantum phase estimation and by an iterative independent set of Hadamard tests

A case of peripheral ameloblastoma of retromolar trigone: Histopathological and immunohistochemical profile

Peripheral ameloblastoma (PA) is a rare and unusual entity with histological characteristics similar to those of the common intraosseous ameloblastoma. In this paper, we present a case of PA in a 44-year-old male affecting the right retromolar trigone area along with its immunohistochemical profile using CK19 and Ber-EP4 markers

Controversies in Odontogenic Tumours : Review

Odontogenic tumours are lesions that occur solely within the oral cavity and are so named because of their origin from the odontogenic (i.e. tooth-forming) apparatus. Odontogenic tumours comprise a variety of lesions ranging from non-neoplastic tissue proliferations to benign or malignant neoplasms. However, controversies exist regarding the pathogenesis, categorisation and clinical and histological variations of these tumours. The recent 2017 World Health Organization classification of odontogenic tumours included new entities such as primordial odontogenic tumours, sclerosing odontogenic carcinomas and odontogenic carcinosarcomas, while eliminating several previously included entities like keratocystic odontogenic tumours and calcifying cystic odonogenic tumours. The aim of the present review article was to discuss controversies and recent concepts regarding odontogenic tumours so as to increase understanding of these lesions

Nuclear structure constraints on nucleosynthesis

Nuclear structure properties of proton rich nuclei at the limits of stability are an importance input for nuclear astrophysics models. The theoretical interpretation of the experimental decay data of these nuclei, makes possible the assignment of nuclear levels, and proton separation energies, crucial to understand how the rp process for the formation of the elements flows, and how it ends

Cloning, characterization and expression analysis of <em>APETALA2</em> genes of <em>Brassica juncea</em> (L.) Czern.

604-610The APETALA2/Ethylene-Responsive Factor (AP2/ERF) is one of the largest gene families encoding several plant specific transcription factors. It plays significant roles in growth and development process, biotic and abiotic stresses, and responses to hormones. AP2 is a homeotic gene governing floral meristem specification, floral organ determination and floral homeotic gene expression in Arabidopsis. The basic structure of AP2 gene was unchanged during evolution in diploid species. The present study was undertaken to find whether AP2 has undergone any change in structure or expression pattern during evolution of allopolyploid Brassica juncea. We cloned AP2 orthologs and c-DNAs from B. juncea and B. nigra. B. juncea was found to carry three AtAP2 orthologs. Comparison of BjAP2 genes with AP2 orthologs from progenitor species, B. rapa and B. nigra showed that two of the BjAP2 genes were derived from B. rapa and one from B. nigra. BjAP2 genes have retained its characteristic AP2 domain and miR172 complementary sequences. mRNAs originated from three AP2 orthologs were detected in all the tissues examined, namely, leaf, flower buds and seedling, indicating absence of sub-functionalization of AP2 during polyploid evolution. However, one of the B. rapa copies gave alternatively spliced AP2 transcript which lacked the second exon. Consequently, the splice variant could not be translated into functional AP2 protein. Considering that miR172 suppresses translation of AP2 transcripts, the alternatively spliced transcript could still play important regulatory role by limiting the availability of miR172 molecules to bind to functional AP2 transcripts. qRT-PCR analysis of BjAP2 expression in different accessions of B. juncea with contrasting seed size indicated that BjAP2 is not a major determinant of seed size in mustard

Proton emission study as a guide to astrophysical rp process

Proton emitters play an important role in deciding the path of the astrophysical rapid proton capture (rp) process. The lifetime of these nuclei depends on several factors, like the deformation, angular momentum of the emitted proton, residual interaction between valence proton and neutron (especially in case of odd-odd nuclei) and so on. Therefore, it is worth to investigate the structure of proton emitters to understand the rp process path. However, due to lack of data in this exotic region, the theoretical models should be robust and the dependence on the free parameters should be minimal. In this direction, we have developed the first microscopic approach to study the triaxially deformed odd-odd proton emitters. The application of the developed approach to 108I, a recently observed proton emitter to investigate the end cycle of the rp process, is discussed