- Google Open Sources TensorNetwork , A Library For Faster ML And
**Physics**TasksMathematics as a tool to interpret nature's most confounding problems from molecular biology to quantum mechanics has so far been successful. ... read more - Hilbert Space Fragmentation and Many-Body Localization. (arXiv:1906.05709v1 [cond-mat.dis-nn])Investigating many-body localization (MBL) using exact numerical methods is limited by the exponential growth of the Hilbert space. However, localized eigenstates display multifractality and only extend over a vanishing fraction of the Hilbert space. Here, building on this remarkable property, we develop a simple yet efficient decimation scheme to discard ... read more
- Direct optical excitation of an NV center via a nanofiber Bragg-cavity: A theoretical simulation. (arXiv:1906.05707v1 [quant-ph])Direct optical excitation of a nitrogen-vacancy (NV) center in nanodiamond by light via a nanofiber is of interest for all-fiber-integrated quantum applications. However, the background light induced by the excitation light via the nanofiber is problematic as it has the same optical wavelength as the emission light from the NV ... read more
- Garrett approximation revisited. (arXiv:1906.05697v1 [quant-ph])Three variants of the Garrett approximation are studied and their accuracy is analyzed, for symmetric and asymmetric square wells. Quite surprisingly, the simplest variants are also the most accurate. The applications to quantum wells, quantum dots and capillary neutron guides are briefly discussed. ... read more
- The complexity of the vertex-minor problem. (arXiv:1906.05689v1 [math.CO])A graph H is a vertex-minor of a graph G if it can be reached from G by the successive application of local complementations and vertex deletions. Vertex-minors have been the subject of intense study in graph theory over the last decades and have found applications in other fields such ... read more
- Invariant Off-Diagonality: SICs as Equicoherent Quantum States. (arXiv:1906.05637v1 [quant-ph])Coherence, treated as a resource in quantum information theory, is a basis-dependent quantity. Looking for states that have constant coherence under canonical changes of basis yields highly symmetric structures in state space. For the case of a qubit, we find an easy construction of qubit SICs (Symmetric Informationally Complete POVMs). ... read more
- Control of quantum memory assisted entropic uncertainty lower bound for topological qubits in open quantum system through environment. (arXiv:1906.05613v1 [quant-ph])The uncertainty principle is one of the most important issues that clarify the distinction between classical and quantum theory. This principle sets a bound on our ability for prediction of the measurement outcomes of two incompatible observable precisely. Uncertainty principle can be formulated via Shannon entropies of the probability distributions ... read more
- Negativity of quasiprobability distribtions as a measure of nonclassicality. (arXiv:1906.05579v1 [quant-ph])We demonstrate that the negative volume of any $s$-paramatrized quasiprobability, including the Glauber-Sudashan $P$-function, can be consistently defined and forms a continuous hierarchy of nonclassicality measures that are linear optical monotones. These measures therefore belong to an operational resource theory of nonclassicality based on linear optical operations. The negativity of ... read more
- Experimental hybrid quantum-classical reinforcement learning by boson sampling: how to train a quantum cloner. (arXiv:1906.05540v1 [quant-ph])We report on experimental implementation of a machine-learned quantum gate driven by a classical control. The gate learns optimal phase-covariant cloning in a reinforcement learning scenario having fidelity of the clones as reward. In our experiment, the gate learns to achieve nearly optimal cloning fidelity allowed for this particular class ... read more
- Analysis of assumptions in BIG Bell Test experiments. (arXiv:1906.05503v1 [quant-ph])Recent group of experiments tested local realism with random choices prepared by humans. These various tests were subject to additional assumptions, which lead to loopholes in the interpretations of almost all the experiments. Among these assumptions is fair sampling, no signaling and faithful quantum model. We examined the data from ... read more
- Entanglement after Quantum Quenches in Lifshitz Scalar Theories. (arXiv:1906.05476v1 [hep-th])We study the time evolution of the entanglement entropy after quantum quenches in Lifshitz free scalar theories, with the dynamical exponent $z>1$, by using the correlator method. For quantum quenches we consider two types of time-dependent mass functions: end-critical-protocol (ECP) and cis-critical-protocol (CCP). In both cases, at early times the ... read more
- Emergent Gauge Symmetries and Quantum Operations. (arXiv:1906.05464v1 [quant-ph])The algebraic approach to quantum physics emphasizes the role played by the structure of the algebra of observables and its relation to the space of states. An important feature of this point of view is that subsystems can be described by subalgebras, with partial trace being replaced by the more ... read more
- Cooperative spontaneous emission via renormalization approach: Classical versus semi-classical effects. (arXiv:1906.05719v1 [physics.atom-ph])We address the many-atom emission of a dilute cloud of two-level atoms through a renormalized perturbation theory. An analytical solution for the truncated coupled-dipole equations is derived, which contains an effective spectrum associated to the initial conditions. Our solution is able to distinguish precisely classical from semi-classical predictions for large ... read more