361 citations · 1.6k across the 33 of their papers we have counts for
34 papers
Measurement-induced integer families of critical dynamical scaling in quantum many-body systems
Zuo Wang, Shi-Liang Zhu, Li-Jun Lang +1
A quantum many-body system can undergo transitions in the presence of continuous measurement. In this work, we find that a generic class of critical dynamical scaling behavior can…
Topological Transitions with an Imaginary Aubry-Andre-Harper Potential
Bofeng Zhu, Li-Jun Lang, Qiang Wang +2
We study one-dimensional lattices with imaginary-valued Aubry-Andre-Harper (AAH) potentials. Such lattices can host edge states with purely imaginary eigenenergies, which differ fr…
Quantum circuit for measuring an operator's generalized expectation values and its applications to non-Hermitian winding numbers
Ze-Hao Huang, Peng He, Li-Jun Lang +1
We propose a general quantum circuit based on the swap test for measuring the quantity of an arbitrary operator with respect to two quantum stat…
Real-space condensation of reciprocal active particles driven by spontaneous symmetry breaking induced nonreciprocity
Wei-chen Guo, Zuo Wang, Pei-fang Wu +3
We investigate the steady-state and dynamical properties of a reciprocal many-body system consisting of self-propelled active particles with local alignment interactions that exist…
Bernstein-Kouchnirenko-Khovanskii with a symmetry
Alexander Esterov, Lionel Lang
A generic polynomial f(x,y,z) with a prescribed Newton polytope defines a symmetric spatial curve f(x,y,z)=f(y,x,z)=0. We study its geometry: the number, degree and genus of its ir…
Permuting the roots of univariate polynomials whose coefficients depend on parameters
Alexander Esterov, Lionel Lang
We address two interrelated problems concerning the permutation of roots of univariate polynomials whose coefficients depend on parameters. First, we compute the Galois group of po…
Gain/loss effects on spin-orbit coupled ultracold atoms in two-dimensional optical lattices
Zhi-Cong Xu, Ziyu Zhou, Enhong Cheng +2
Due to the fundamental position of spin-orbit coupled ultracold atoms in the simulation of topological insulators, the gain/loss effects on these systems should be evaluated when c…
Emergent Mott insulators and non-Hermitian conservation laws in an interacting bosonic chain with noninteger filling and nonreciprocal hopping
Zuo Wang, Li-Jun Lang, Liang He
We investigate the ground state and quantum dynamics of an interacting bosonic chain with the nonreciprocal hopping. In sharp contrast to its Hermitian counterpart, the ground stat…
Non-Hermitian topological end breathers
Li-Jun Lang, Shi-Liang Zhu, Y. D. Chong
Nonlinearities in lattices with topologically nontrivial band structures can give rise to topological solitons, whose properties differ from both conventional lattice solitons and…
Patchworking the Log-critical locus of planar curves
Lionel Lang, Arthur Renaudineau
We establish a patchworking theorem à la Viro for the Log-critical locus of algebraic curves in . As an application, we prove the existence of projective curves o…
Dynamical robustness of topological end states in nonreciprocal Su-Schrieffer-Heeger models with open boundary conditions
Li-Jun Lang, Yijiao Weng, Yunhui Zhang +2
For non-Hermitian quantum models, the dynamics is apparently not reflected by the static properties, e.g., the complex energy spectrum, because of the nonorthogonality of the right…
A note on the Severi problem for toric surfaces
Lionel Lang, Ilya Tyomkin
In this note, we make a step towards the classification of toric surfaces admitting reducible Severi varieties. We generalize the results of [Lan19, Tyo13, Tyo14], and provide two…
Skin superfluid, topological Mott insulators, and asymmetric dynamics in interacting non-Hermitian Aubry-Andre-Harper models
Dan-Wei Zhang, Yu-Lian Chen, Guo-Qing Zhang +3
Non-Hermitian quantum many-body systems are a fascinating subject to be explored. Using the generalized density matrix renormalisation group method and complementary exact diagonal…
Braid monodromy of univariate fewnomials
Alexander Esterov, Lionel Lang
Let be the space of non-singular, univariate polynomials of degree . The Viète map $\mathscr{V} : \mathcal{C}_d \rightarrow Sym_d(\mathbb…
Non-Hermitian Topological Anderson Insulators
Dan-Wei Zhang, Ling-Zhi Tang, Li-Jun Lang +2
Non-Hermitian systems can exhibit unique topological and localization properties. Here we elucidate the non-Hermitian effects on disordered topological systems by studying a non-He…
On the number of intersection points of the contour of an amoeba with a line
Lionel Lang, Boris Shapiro, Eugenii Shustin
In this note, we investigate the maximal number of intersection points of a line with the contour of hypersurface amoebas in . We define the latter number to be the $…
Monodromy of rational curves on toric surfaces
Lionel Lang
For an ample line bundle on a complete toric surface , we consider the subset of irreducible, nodal, rational cur…
Interplay of non-Hermitian skin effects and Anderson localization in non-reciprocal quasiperiodic lattices
Hui Jiang, Li-Jun Lang, Chao Yang +2
Non-Hermiticity from non-reciprocal hoppings has been shown recently to demonstrate the non-Hermitian skin effect (NHSE) under open boundary conditions (OBCs). Here we study the in…
Sparse polynomial equations and other enumerative problems whose Galois groups are wreath products
Alexander Esterov, Lionel Lang
We introduce a new technique to prove connectivity of subsets of covering spaces (so called inductive connectivity), and apply it to Galois theory of problems of enumerative geomet…
Effects of Non-Hermiticity on Su-Schrieffer-Heeger Defect States
Li-Jun Lang, You Wang, Hailong Wang +1
We study the emergence and disappearance of defect states in the complex Su-Schrieffer-Heeger (cSSH) model, a non-Hermitian one-dimensional lattice model containing gain and loss o…
Topologically Enhanced Harmonic Generation in a Nonlinear Transmission Line Metamaterial
You Wang, Li-Jun Lang, Ching Hua Lee +2
Nonlinear transmission lines (NLTLs) are nonlinear electronic circuits commonly used for parametric amplification and pulse generation. It has previously been shown that harmonic g…
Non-Hermitian dynamics of slowly-varying Hamiltonians
Hailong Wang, Li-Jun Lang, Y. D. Chong
We develop a theoretical description of non-Hermitian time evolution that accounts for the break- down of the adiabatic theorem. We obtain closed-form expressions for the time-depe…
The vanishing cycles of curves in toric surfaces II
Rémi Crétois, Lionel Lang
We resume the study initiated in \cite{CL}. For a generic curve in an ample linear system on a toric surface , a vanishing cycle of is an isoto…
Amoebas of curves and the Lyashko-Looijenga map
Lionel Lang
For any curve in a toric surface , we study the critical locus of the moment map from to its compactified amoeba $μ(\mathcal{V})…