Search results for "Quantum simulator"
showing 10 items of 63 documents
Quantum state engineering using one-dimensional discrete-time quantum walks
2017
Quantum state preparation in high-dimensional systems is an essential requirement for many quantum-technology applications. The engineering of an arbitrary quantum state is, however, typically strongly dependent on the experimental platform chosen for implementation, and a general framework is still missing. Here we show that coined quantum walks on a line, which represent a framework general enough to encompass a variety of different platforms, can be used for quantum state engineering of arbitrary superpositions of the walker's sites. We achieve this goal by identifying a set of conditions that fully characterize the reachable states in the space comprising walker and coin, and providing …
Experimental benchmarking of quantum control in zero-field nuclear magnetic resonance
2017
Zero-field nuclear magnetic resonance (NMR) provides complementary analysis modalities to those of high-field NMR and allows for ultra-high-resolution spectroscopy and measurement of untruncated spin-spin interactions. Unlike for the high-field case, however, universal quantum control -- the ability to perform arbitrary unitary operations -- has not been experimentally demonstrated in zero-field NMR. This is because the Larmor frequency for all spins is identically zero at zero field, making it challenging to individually address different spin species. We realize a composite-pulse technique for arbitrary independent rotations of $^1$H and $^{13}$C spins in a two-spin system. Quantum-inform…
Optical Shielding of Destructive Chemical Reactions between Ultracold Ground-State NaRb Molecules
2020
Polar quantum gases represent promising platforms for studying many-body physics and strongly correlated systems with possible applications e.g. in quantum simulation or quantum computation. Due to their large permanent electric dipole moment polar molecules in electric field exhibit strong long-range anisotropic dipole-dipole interactions (DDIs). The creation and trapping of ultracold dipolar diatomic molecules of various species are feasible in many experimental groups nowadays. However long time trapping is still a challenge even in the case of the so called nonreactive molecules which are supposed to be immune against inelastic collisions in their absolute ground state [1] . Various hyp…
Highly controlled optical transport of cold atoms into a hollow-core fiber
2018
We report on an efficient and highly controlled cold atom hollow-core fiber interface, suitable for quantum simulation, information, and sensing. The main focus of this manuscript is a detailed study on transporting cold atoms into the fiber using an optical conveyor belt. We discuss how we can precisely control the spatial, thermal, and temporal distribution of the atoms by, e.g., varying the speed at which the atoms are transported or adjusting the depth of the transport potential according to the atomic position. We characterize the transport of atoms to the fiber tip for these different parameters. In particular, we show that by adapting the transport potential we can lower the temperat…
Quantifying, characterizing, and controlling information flow in ultracold atomic gases
2011
We study quantum information flow in a model comprising of an impurity qubit immersed in a Bose-Einstein condensed reservoir. We demonstrate how information flux between the qubit and the condensate can be manipulated by engineering the ultracold reservoir within experimentally realistic limits. We place a particular emphasis on non-Markovian dynamics, characterized by a reversed flow of information from the background gas to the qubit and identify a controllable crossover between Markovian and non-Markovian dynamics in the parameter space of the model.
Quantum many-body dynamics of coupled double-well superlattices
2008
We propose a method for controllable generation of non-local entangled pairs using spinor atoms loaded in an optical superlattice. Our scheme iteratively increases the distance between entangled atoms by controlling the coupling between the double wells. When implemented in a finite linear chain of 2N atoms, it creates a triplet valence bond state with large persistency of entanglement (of the order of N). We also study the non-equilibrium dynamics of the one-dimensional ferromagnetic Heisenberg Hamiltonian and show that the time evolution of a state of decoupled triplets on each double well leads to the formation of a highly entangled state where short-distance antiferromagnetic correlatio…
COMPLEXITY, NOISE AND QUANTUM INFORMATION ON ATOM CHIPS
2008
The realization of quantum logic gates with neutral atoms on atom chips is investigated, including realistic features, such as noise and actual experimental setups.
Trapped Rydberg ions: A new platform for quantum information processing
2020
Abstract In this chapter, we present an overview of experiments with trapped Rydberg ions and outline the advantages and challenges of developing applications of this new platform for quantum computing, sensing, and simulation. Trapped Rydberg ions feature several important properties, unique in their combination: they are tightly bound in a harmonic potential of a Paul trap, in which their internal and external degrees of freedom can be controlled in a precise fashion. High fidelity state preparation of both internal and motional states of the ions has been demonstrated, and the internal states have been employed to store and manipulate qubit information. Furthermore, strong dipolar intera…
Quantum simulation of the spin-boson model with a microwave circuit
2017
We consider superconducting circuits for the purpose of simulating the spin-boson model. The spin-boson model consists of a single two-level system coupled to bosonic modes. In most cases, the model is considered in a limit where the bosonic modes are sufficiently dense to form a continuous spectral bath. A very well known case is the ohmic bath, where the density of states grows linearly with the frequency. In the limit of weak coupling or large temperature, this problem can be solved numerically. If the coupling is strong, the bosonic modes can become sufficiently excited to make a classical simulation impossible. Here, we discuss how a quantum simulation of this problem can be performed …
Ideas in the History of Nano/Miniaturization and (Quantum) Simulators: Feynman, Education and Research Reorientation in Translational Science
2015
Cultural history of nanominiaturization, computing, quantum computing and simulating is necessary to comprehend human character and place it in the whole of living beings. Ideas in the history of physics by Feynman, etc. are valued by the questions that generate. A series of questions, answers and hypothesis introduces the nature of the history of nanominiaturization, providing facts. Nanotechnology adds a third dimension to the periodic table of the elements. Thinking about computers was useful. It must do with learning computers possibilities and physics potential. Provisional conclusions follow. (1) Nature (space–time) is not classical but discrete; quantization is a different kind of ma…