A journey through several theoretical approaches to measurement-induced phase transitions is presented: exact results are shown be possible in some cases, and new lines of inquiry opened up, with outstanding questions clearly delineated.

We report a study of the magnetocaloric effect in ternary alloy system Ni50Mn34In16. This undergoes an austenite–martensite phase transition, and change magnetic entropy is found to be quite large across this martensitic transition. due increase induced by application external field can lead inverse effect. Isothermal variation magnetization exhibits hysteresis Ni50Mn34In16 But spite losses, effective refrigerant capacity obtained material over wide temperature interval.

We set out a general protocol for steering the state of quantum system from an arbitrary initial towards chosen target by coupling it to auxiliary degrees freedom. The requires multiple repetitions elementary step: during each step evolves fixed time while coupled freedom (which we term 'detector qubits') that have been prepared in specified state. detectors are discarded at end step, or equivalently, their is determined projective measurement with unbiased average over all outcomes....

We present results of detailed ac susceptibility, magnetization and specific heat measurements in Heusler alloys Ni50Mn34In16 Ni50Mn34Sn16. These undergo a paramagnetic to ferromagnetic transition around 305 K, which is followed by martensitic the temperature regime 220 K. Inside martensite phase both show signatures field-induced from austenite phase. Both field- temperature-induced martensite–austenite transitions are relatively sharp Ni50Mn34In16. estimate isothermal magnetic entropy...

We present the results of magnetocaloric effect (MCE) studies in polycrystalline Fe–Rh alloy over a temperature range 250–345 K across first order antiferromagnetic to ferromagnetic transition. By measuring MCE under various thermomagnetic histories, contrary long held belief, we show here explicitly that giant near room does not vanish after field cycle. In spite fact virgin magnetization curve is lost cycle temperature, reproducibility multiple cycles can be achieved by properly choosing...

Periodically driven, or Floquet, disordered quantum systems have generated many unexpected discoveries of late, such as the anomalous Floquet Anderson insulator and discrete time crystal. Here, we report emergence an entire band multifractal wavefunctions in a periodically driven chain non-interacting particles subject to spatially quasiperiodic disorder. Remarkably, this multifractality is robust that it does not require any fine-tuning model parameters, which sets apart from known critical...

We study the dynamics of a one-dimensional lattice model hard core bosons which is initially in superfluid phase with current being induced by applying twist at boundary. Subsequently, removed and system subjected to periodic $\de$-function kicks staggered on-site potential. present analytical expressions for work done limit an infinite number kicks. Using these, we show that (work done) exhibit dips (peaks) as function driving frequency eventually saturates zero (a finite value) large...

The authors approach the problem of many-body localization on Fock space, with nodes and links representing states Hamiltonian matrix-elements. maps exactly onto a tight-binding model complex high-dimensional graph nontrivial correlated disorder. These correlations are shown to lie at heart localization. central result from this theory is that in Fock-space disorder must be maximal for localized phase stable.

We introduce a model of nonunitary quantum dynamics that exhibits infinitely long-lived discrete spatiotemporal order robust against any unitary or dissipative perturbation. Ergodicity is evaded by combining sequence projective measurements with local feedback rule inspired Toom's "north-east-center" classical cellular automaton. The in question only partially collapse the wave function system, allowing some coherence to persist. demonstrate our claims using numerical simulations Clifford...

The magnetoresistance (MR) in polycrystalline colossal magnetoresistive compounds follows a behavior different from single crystals below the ferromagnetic transition temperature. This difference is usually attributed to spin polarized tunneling at grain boundaries of sample. Here we derive theoretical expression for contribution granular systems under mean field approximation. We apply this model our experimental data on half metallic ferromagnet La0.7Sr0.3MnO3, and find that predictions...

Coexisting ferromagnetic and antiferromagnetic phases over a range of temperature as well magnetic field have been reported in many materials current interest, showing disorder-broadened 1st order transitions. Anomalous history effects observed magnetization resistivity are being explained invoking the concepts kinetic arrest akin to glass From measurements traversing novel paths field-temperature space, we obtain intriguing result that regions sample which can be supercooled lower...

When a Dirac semimetal is subject to circularly polarized laser, it predicted that the cone splits into two Weyl nodes and nonequilibrium transient state called Floquet realized. We focus on previously unexplored low-frequency regime, where upper lower bands resonantly couple with each other through multi-photon processes, which realistic situation in solid ultrafast pump-probe experiments. find series of new emerging pairs when replica hybridize other. The nature regard number, locations,...

Many-body localisation is studied in a disordered quantum spin-1/2 chain with long-ranged power-law interactions, and distinct exponents for interactions between longitudinal transverse spin components. Using self-consistent mean-field theory centring on the local propagator Fock space its associated self-energy, phase diagram obtained as function of disorder strength random fields acting spin-components. Analytical results are corroborated using well-studied complementary numerical...

We study classical percolation models in Fock space as proxies for the quantum many-body localisation (MBL) transition. Percolation rules are defined two of disordered spin-chains using their microscopic Hamiltonians and topologies associated Fock-space graphs. The transition is revealed by statistics cluster sizes, obtained exact enumeration finite-sized systems. As a function disorder strength, typical size shows from volume law to sub-volume law, directly analogous behaviour eigenstate...

Condensed matter systems realizing Weyl fermions exhibit striking phenomenology derived from their topologically protected surface states as well chiral anomalies induced by electromagnetic fields. More recently, inhomogeneous strain or magnetization were predicted to result in electric ${\mathbf{E}}_{5}$ and magnetic ${\mathbf{B}}_{5}$ fields, which modify enrich the anomaly with additional terms. In this Rapid Communication, we develop a lattice-based approach describe anomaly, involves...

By varying the disorder realisation in many-body localised (MBL) phase, we investigate influence of resonances on spectral properties. The standard theory MBL phase is based existence local integrals motion (LIOM), and eigenstates time evolution operator can be described as LIOM configurations. We show that smooth variations give rise to avoided level crossings, identify these with between Through this parametric approach, develop a for terms properties non-resonant LIOM. This framework...

We formulate a theory for resonances in the many-body localized (MBL) phase of disordered quantum spin chains terms local observables. A key result is to show that there are universal correlations between matrix elements observables and level spectrum. This reveals how encode energy scales associated with resonance, thereby allowing us these energies power-law-distributed. Using results, we calculate analytically distributions polarizations eigenstate fidelity susceptibilities. The first...

Using resonant magnetic x-ray photon correlation spectroscopy, we show that the domains of a spiral antiferromagnet enter jammed state at onset long-range order. We find slow thermal fluctuations domain walls exhibit compressed exponential relaxation with an exponent 1.5 found in wide variety solidlike systems and can be qualitatively explained terms stress release stressed network. As temperature decreases, energy barrier for becomes large enough to arrest further wall fluctuations, freeze...

This paper shows that local kinetic constraints in random many-body Hamiltonians can lead to ergodicity breaking, despite the Hilbert space not fragmenting. is purely due constraints, unconstrained system ergodic. The mechanism underlying emergence of localized phase qualitatively different from localization locally disordered Hamiltonians.

The authors address the question of time crystallinity in a dissipative periodically-driven quantum system, identifying general conditions for its stability. paper concludes that this type crystal is conceptually and phenomenologically different from unitary discrete crystals.

We explore the Fock-space structure of eigenstates across many-body localization (MBL) transition in a disordered, interacting quantum spin-$\frac{1}{2}$ chain. Eigenstate expectation values spatially local observables, which distinguish an MBL phase from ergodic one, can be represented terms eigenstate amplitudes on Fock space. Motivated by this, we introduce and study spatial correlations From these, correlation length emerges, is found to vary discontinuously transition, intimately...

We implement a recursive Green's function method to extract the Fock space (FS) propagator and associated self-energy across many-body localization (MBL) transition, for one-dimensional interacting fermions in random on-site potential. show that typical value of imaginary part local FS self-energy, ${\mathrm{\ensuremath{\Delta}}}_{t}$, related decay rate an initially localized state, acts as probabilistic order parameter thermal MBL phase transition can be used characterize critical...

We demonstrate numerically that a robust and unusual multifractal regime can emerge in one-dimensional quantum chain with maximally correlated disorder, above threshold disorder strength. This is preceded by mixed an extended at weaker strengths, the former hosting both eigenstates. The states we find are markedly different from conventional their structure, as they reside approximately uniformly over continuous segment of chain, lengths these segments scale nontrivially system size....

In this letter we report large magnetoresistance (MR) in ceramic samples of La1−xSrxMnO3 (0.1≤x≤0.4) the temperature range 4.2 K≤T≤350 K fields up to 6 T. We find that a negative and isotopic MR exists for whole composition studied absolute value resistivity change on application magnetic field is more with lower x which have higher resistivity. occurs ferromagnetic state only has close relation magnetization M.

A near room-temperature martensitic transition is observed in the ferromagnetic austenite state of ${\text{Ni}}_{50}{\text{Mn}}_{34}{\text{In}}_{16}$ alloy with 2% Cu substitution at Ni site. Application magnetic field martensite induces a reverse this alloy. dc magnetization, magnetoresistance and strain measurements reveal that associated there exist large magnetocaloric effect, magnetoresitance magnetic-field temperature-induced strain. This NiMnIn system thus an example emerging class...