895 research outputs found
Scars from protected zero modes and beyond in quantum link and quantum dimer models
No full textWe demonstrate the presence of anomalous high-energy eigenstates, or
many-body scars, in quantum link and quantum dimer models on square and
rectangular lattices. In particular, we consider the paradigmatic
Rokhsar-Kivelson Hamiltonian where
() is defined as a sum of terms on elementary
plaquettes that are diagonal (off-diagonal) in the computational basis. Both
these interacting models possess an exponentially large number of mid-spectrum
zero modes in system size at that are protected by an index theorem
preventing any mixing with the nonzero modes at this coupling. We classify
different types of scars for both at zero
and finite winding number sectors complementing and significantly generalizing
our previous work [Banerjee and Sen, Phys. Rev. Lett. 126, 220601 (2021)]. The
scars at finite show a rich variety with those that are composed
solely from the zero modes of , those that contain
an admixture of both the zero and the nonzero modes of
, and finally those composed solely from the
nonzero modes of . We give analytic expressions for
certain "lego scars" for the quantum dimer model on rectangular lattices where
one of the linear dimensions can be made arbitrarily large, with the building
blocks (legos) being composed of emergent singlets and other more complicated
entangled structures.Comment: Version 3 addressing the comments of the Referees, slightly modified
text, added references; 39 pages, 22 figures; Submission to SciPost Physic
sj-pdf-1-jim-10.1177_1045389X211032281 – Supplemental material for Enhanced low-frequency vibration energy harvesting with inertial amplifiers
No full textSupplemental material, sj-pdf-1-jim-10.1177_1045389X211032281 for Enhanced low-frequency vibration energy harvesting with inertial amplifiers by Sondipon Adhikari and Arnab Banerjee in Journal of Intelligent Material Systems and Structures</p
Weak universality induced by Q = ± 2e charges at the deconfinement transition of a (2+1)-dimensional U(1) lattice gauge theory
No full textMatter-free lattice gauge theories (LGTs) provide an ideal setting to understand confinement to deconfinement transitions at finite temperatures, which is typically due to the spontaneous breakdown (at large temperatures) of the center symmetry associated with the gauge group. Close to the transition, the relevant degrees of freedom (Polyakov loop) transform under these center symmetries, and the effective theory depends on only the Polyakov loop and its fluctuations. As shown first by Svetitsky and Yaffe, and subsequently verified numerically, for the U(1) LGT in (2 þ 1) dimensions, the transition is in the 2D XY universality class, while for the Z2 LGT, it is in the 2D Ising universality class. We extend this classic scenario by adding higher charged matter fields and show that the critical exponents γ and ν can change continuously as a coupling is varied, while their ratio is fixed to the 2D Ising value. While such weak universality is well known for spin models, we demonstrate this for LGTs for the first time. Using an efficient cluster algorithm, we show that the finite temperature phase transition of the U(1) quantum link LGT in the spin S ¼ 12 representation is in the 2D XY universality class, as expected. On the addition of Q ¼ ±2e charges distributed thermally, we demonstrate the occurrence of weak universality
LMCT transition-based red-light photochemotherapy using a tumour-selective ferrocenyl iron( iii ) coumarin conjugate
No full text
Sublattice scars and beyond in two-dimensional quantum link lattice gauge theories
No full textIn this article, we elucidate the structure and properties of a class of
anomalous high-energy states of matter-free quantum link gauge theory
Hamiltonians using numerical and analytical methods. Such anomalous states,
known as quantum many-body scars in the literature, have generated a lot of
interest due to their athermal nature. Our starting Hamiltonian is , where
is a real-valued coupling, and
() are summed local diagonal (off-diagonal)
operators in the electric flux basis acting on the elementary plaquette
. The spectrum of the model in its spin- representation
on lattices reveal the existence of sublattice scars, , which satisfy for all elementary plaquettes on one sublattice and on the other, while
being simultaneous zero modes or nonzero integer-valued eigenstates of
. We demonstrate a ``triangle relation'' connecting
the sublattice scars with nonzero integer eigenvalues of to particular sublattice scars with
eigenvalues. A fraction of the sublattice
scars have a simple description in terms of emergent short singlets, on which
we place analytic bounds. We further construct a long-ranged parent Hamiltonian
for which all sublattice scars in the null space of become unique ground states and elucidate some of
the properties of its spectrum. In particular, zero energy states of this
parent Hamiltonian turn out to be exact scars of another quantum link
model with a staggered short-ranged diagonal term.Comment: 18 pages, 10 figure
Abstract 5891: DCIS to invasive progression in breast cancer is delayed by restoring CCN5
No full textAbstract
Malignant progression of breast cancer from pre-invasive to invasive lesions remains a mechanistically unknown event and a major challenge in medical research. By revealing the mechanism of action, our new and substantially different approach aims to demonstrate that CCN5/WISP2 might play a role in negative regulation of progression of pre-invasive lesion ductal carcinoma in-situ (DCIS) to invasive carcinoma (IC). DCIS to IC transition results primarily from the loss of the myoepithelial cell (MEC) layer surrounding the breast ducts & lobules and basement membrane (BM) degradation followed by invasion of cancer cells into the surrounding stromal tissue and vasculature. It has been recently discovered that CCN5, a matricellular protein, is highly expressed in DCIS patient specimens and facilitates regression of aggressive phenotypes. Our in-vitro studies with myoepithelial cell lines (MECs) indicate that CCN5 may prevent the DCIS to IC transition through the protection of the MEC layer. CCN5 performs it’s protective role by regulating sonic hedgehog (SHh) expression in MECs. It has been previously shown in separate studies that Neuropilin1 (Nrp1) positively regulates expression of SHh and Nrp1 is exclusively expressed in MEC layer in breast tissues. An extension of our studies indicate that CCN5 might regulate the integrity of the mammary ductal architecture by protecting the MEC layer through a novel Nrp1-SHh signaling axis. Collectively, our studies indicate that regulating CCN5 expression level in breast cancer tissues might help us controlling the rate of progression of the disease from DCIS to an invasive stage.
Citation Format: Sandipto Sarkar, Arnab Ghosh, Gargi Maity, Snigdha Banerjee, Sushanta Banerjee. DCIS to invasive progression in breast cancer is delayed by restoring CCN5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5891. doi:10.1158/1538-7445.AM2017-5891</jats:p
Conformation and interaction of a D,L-alternating peptide with a bilayer membrane: X-ray reflectivity, CD, and FTIR spectroscopy
No full textPeptides with alternating amino acid configuration provide helical secondary structures that are especially known from the membrane channel and pore-forming gramicidin A. In analogy to this natural D,L-alternating pentadecapeptide, the potential of D,L-alternating peptides for membrane insertion is investigated using the model dodecamer peptide H-(Phe-Tyr)(5)-Trp-Trp-OH. This aromatic peptide is introduced as a novel pore-forming synthetic analogue of gramicidin A. It forms a well-organized homodimer similar to one of the gromicidin A transmembrane motifs
Prominent quantum many-body scars in a truncated Schwinger model
No full textThe high level of control and precision achievable in current synthetic
quantum matter setups has enabled first attempts at quantum-simulating various
intriguing phenomena in condensed matter physics, including those probing
thermalization or its absence in closed quantum systems. In a recent work
[Desaules \textit{et al.} [arXiv:2203.08830], we have shown that quantum
many-body scars -- special low-entropy eigenstates that weakly break ergodicity
in nonintegrable systems -- arise in spin- quantum link models that converge
to D lattice quantum electrodynamics (Schwinger model) in the
Kogut--Susskind limit . In this work, we further demonstrate that
quantum many-body scars exist in a truncated version of the Schwinger model,
and are qualitatively more prominent than their counterparts in spin-
quantum link models. We illustrate this by, among other things, performing a
finite- scaling analysis that strongly suggests that scarring persists in
the truncated Schwinger model in the limit . Although it does not
asymptotically converge to the Schwinger model, the truncated formulation is
relevant to synthetic quantum matter experiments, and also provides fundamental
insight into the nature of quantum many-body scars, their connection to lattice
gauge theories, and the thermalization dynamics of the latter. Our conclusions
can be readily tested in current cold-atom setups.Comment: 23 pages, 19 figures, journal articl
- …
