Response to defects in multipartite and bipartite entanglement of isotropic quantum spin networks

Roy, Sudipto Singha; Dhar, Himadri Shekhar; Rakshit, Debraj; SenDe, Aditi; Sen, Ujjwal

doi:10.1103/physreva.97.052325

Cited by 8 publications

(7 citation statements)

References 94 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast to the infinite temperature case, the expectation value p 0 t generically takes values different from 1/4, however. The SU(2) invariance determines the form of the two-spin density matrix to be [26],…”

Section: Two-spin Density Matrix and Full Counting Statistics At Half...mentioning

confidence: 99%

Signatures of correlated magnetic phases in the two-spin density matrix

2019

View full text Add to dashboard Cite

Experiments with quantum gas microscopes have started to explore the antiferromagnetic phase of the twodimensional Fermi-Hubbard model and effects of doping with holes away from half filling. In this work we show how direct measurements of the system averaged two-spin density matrix and its full counting statistics can be used to identify different correlated magnetic phases with or without long-range order. We discuss examples of phases which are potentially realized in the Hubbard model close to half filling, including antiferrromagnetically ordered insulators and metals, as well as insulating spin-liquids and metals with topological order. For these candidate states we predict the doping-and temperature dependence of local correlators, which can be directly measured in current experiments.Ultracold atomic gases in optical lattices provide a versatile platform to study strongly correlated phases of matter in a setting with unprecedented control over Hamiltonian parameters [1,2]. Moreover, the development of quantum gas microscopes now allows for the direct measurement of real space correlation functions with single site resolution in important model systems like the Fermi-Hubbard model, giving access to viable information that can be used to identify various quantum states of matter. Using state of the art technology the many-body wavefunction can now be imaged on a singlesite and single-fermion level [3-7] and even the simultaneous detection of spin and charge (i.e. particle-number) degrees of freedom has been achieved [6]. In combination with the capability to perform local manipulations, new insights can be obtained into the microscopic properties of strongly correlated quantum many-body systems, which are difficult to access in traditional solid state systems. For example, the hidden string order underlying spin-charge separation in the onedimensional t − J model has been directly revealed in a quantum gas microscope [8]. Ultracold atom experiments have also revealed charge ordering in the attractive Fermi-Hubbard model at half filling [9] and observed longer-ranged antiferromagnetic (AFM) correlations [10,11]. Furthermore transport properties of the two-dimensional Fermi-Hubbard model were investigated independently for spin and charge degrees of freedom by exposing the system to an external field in the linear response regime [12,13], where clear signatures of bad metal behaviour have been detected in the temperature dependence of the charge conductivity [13]. In all these settings, the ultracold atom toolbox can now be applied to gain new insights.One of the big open problems in the field of strongly correlated electrons is to understand the fate of the AFM Mott insulator in quasi-two-dimensional square lattice systems upon doping it with holes. This problem is particularly relevant in the context of the so-called pseudogap phase in underdoped high-temperature cuprate superconductors [14]. In the last decades many works have shown that the two-dimensional one band Hubbard model below half filling capture...

show abstract

Section: Two-spin Density Matrix and Full Counting Statistics At Half...mentioning

confidence: 99%

Signatures of correlated magnetic phases in the two-spin density matrix

2019

View full text Add to dashboard Cite

show abstract

“…The RVB gas description of the superconducting spingap phase of the 1D t-J Hamiltonian, at low electron density, has a remarkable significance, since it allows for the study related to the phase properties of this model and beyond, using the RVB ansatz [21,38,39] under suitable doping. Hence, even for moderate-sized systems, where exact diagonalization is not possible, the doped RVB ansatz opens up the possibility of investigating different properties of the t-J Hamiltonian [40] using tensor network [41] or other approximate approaches [42]. Fig.…”

Section: Ground State Phase At Low Electron Densitiesmentioning

confidence: 99%

Adiabatic freezing of entanglement with insertion of defects in a one-dimensional Hubbard model

Das¹,

Roy²,

Dhar³

et al. 2018

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

We report on ground state phases of a doped one-dimensional Hubbard model, which for large onsite interactions is governed by the t-J Hamiltonian, where the extant entanglement is immutable under perturbative or sudden changes of system parameters, a phenomenon termed as adiabatic freezing. We observe that in the metallic Luttinger liquid phase of the model bipartite entanglement decays polynomially and is adiabatically frozen, in contrast to the variable, exponential decay in the phase-separation and superconducting spin-gap phases. Significantly, at low fixed electron densities, the spin-gap phase shows remarkable affinity to doped resonating valence bond gas, with multipartite entanglement frozen across all parameter space. We note that entanglement, in general, is sensitive to external perturbation, as observed in several systems, and hitherto, no such invariance or freezing behavior has been reported. arXiv:1708.07005v2 [quant-ph]

show abstract

“…In an experimental study investigating the ground state of the one-dimensional quantum Ising model in a transverse magnetic field, by using a nuclear magnetic resonance (NMR) setup, monogamy scores of negativity and quantum discord are shown to distinguish between the cases of positive (frustrated phase) and negative (non-frustrated phase) values of J in the ground state of the system [72]. It is interesting to note that monogamy of entanglement has been used to constrain the bipartite entanglement of resonating valence bond states [64][65][66].…”

Section: Characterization Of Quantum Many-body Systemsmentioning

confidence: 99%

“…The monogamy properties of quantum correlations find potential applications in quantum information based protocols like quantum cryptography [3], entanglement distillation [22], quantum state and channel discrimination [44,45,63], and in characterizing quantum many-body systems [64][65][66][67][68][69][70][71][72] as well as in biological processes [73,74]. The key concept of entanglement-based quantum cryptography essentially exploits the trade off in monogamy of quantum correlations, which limits the amount of information that an eavesdropper can extract about the secret key, shared between a sender and a receiver, obtained via measurement on both sides of an entangled state between the sender and the receiver [4,11,75].…”

Section: Introductionmentioning

confidence: 99%

Monogamy of Quantum Correlations - A Review

Dhar

Pal

Rakshit

et al. 2017

Quantum Science and Technology

Self Cite

View full text Add to dashboard Cite

Monogamy is an intrinsic feature of quantum correlations that gives rise to several interesting quantum characteristics which are not amenable to classical explanations. The monogamy property imposes physical restrictions on unconditional sharability of quantum correlations between the different parts of a multipartite quantum system, and thus has a direct bearing on the cooperative properties of states of multiparty systems, including large many-body systems. On the contrary, a certain party can be maximally classical correlated with an arbitrary number of parties in a multiparty system. In recent years, the monogamy property of quantum correlations has been applied to understand several key aspects of quantum physics, including distribution of quantum resources, security in quantum communication, critical phenomena, and quantum biology. In this chapter, we look at some of the salient developments and applications in quantum physics that have been closely associated with the monogamy of quantum discord, and "discord-like" quantum correlation measures.

show abstract

Response to defects in multipartite and bipartite entanglement of isotropic quantum spin networks

Cited by 8 publications

References 94 publications

Signatures of correlated magnetic phases in the two-spin density matrix

Signatures of correlated magnetic phases in the two-spin density matrix

Adiabatic freezing of entanglement with insertion of defects in a one-dimensional Hubbard model

Monogamy of Quantum Correlations - A Review

Contact Info

Product

Resources

About