Organisationen — Kommunikationssystem und Sicherheit

Buerschaper, Cornelius

doi:10.1007/978-3-540-72321-9_9

Cited by 13 publications

(16 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Quantum walks are useful for developing new quantum algorithms [11] and they provide a model for universal quantum computation [12]. They also supply a fertile framework for simulating other quantum systems such as topological phases [13], Anderson localization [14,15], nonlinear δ-kicked quantum systems [16], the breakdown of an electric-field driven system [17] and the creation of entanglement in bipartite systems [18]. Quantum walks can be realized experimentally in various physical systems including ultracold atoms in optical lattices [18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Two-dimensional quantum walk under artificial magnetic field

Yalçınkaya

Gedik

2015

Phys. Rev. A

View full text Add to dashboard Cite

We introduce the Peierls substitution to a two-dimensional discrete-time quantum walk on a square lattice to examine the spreading dynamics and the coin-position entanglement in the presence of an artificial gauge field. We use the ratio of the magnetic flux through the unit cell to the flux quantum as a control parameter. For a given flux ratio, we obtain faster spreading for a small number of steps and the walker tends to be highly localized around the origin. Moreover, the spreading of the walk can be suppressed and decreased within a limited time interval for specific rational values of flux ratio. When the flux ratio is an irrational number, even for a large number of steps, the spreading exhibit diffusive behavior rather than the well-known ballistic one as in the classical random walk and there is a significant probability of finding the walker at the origin. We also analyze the coin-position entanglement and show that the asymptotic behavior vanishes when the flux ratio is different from zero and the coin-position entanglement become nearly maximal in a periodic manner in a long time range.

show abstract

Section: Introductionmentioning

confidence: 99%

Two-dimensional quantum walk under artificial magnetic field

Yalçınkaya

Gedik

2015

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…Note that we are exploring the full SU (2) structure of C(t) with its three independent parameters, which makes it more general than the ones in [14]. Time-dependent walkers were also explored in [16], where instead of C, S was made timedependent, and in [17,18].The general time evolution can be obtained applying U (t), Eq. (1), to an arbitrary state at time t − 1.…”

mentioning

confidence: 99%

Dynamically Disordered Quantum Walk as a Maximal Entanglement Generator

2013

View full text Add to dashboard Cite

We show that the entanglement between the internal (spin) and external (position) degrees of freedom of a qubit in a random (dynamically disordered) one-dimensional discrete time quantum random walk (QRW) achieves its maximal possible value asymptotically in the number of steps, outperforming the entanglement attained by using ordered QRW. The disorder is modeled by introducing an extra random aspect to QRW, a classical coin that randomly dictates which quantum coin drives the system's time evolution. We also show that maximal entanglement is achieved independently of the initial state of the walker, study the number of steps the system must move to be within a small fixed neighborhood of its asymptotic limit, and propose two experiments where these ideas can be tested.

show abstract

“…For realizing a perfect atomic ratchet, quantum resonance conditions should be met, see [11,[16][17][18]. Quantum walks based on the Talbot effect [19] and quantum accelerator modes [20] were proposed, yet never realized due to technical problems in their implementation. We will now describe in detail how to implement a simpler QRW at quantum resonance using an atomic ratchet current whose direction is controlled by two different internal states of the atoms.…”

Section: Quantum Walks At Quantum Resonancementioning

confidence: 99%

Quantum random walk of a Bose-Einstein condensate in momentum space

Summy

Wimberger

2016

Phys. Rev. A

View full text Add to dashboard Cite

Each step in a quantum random walk is typically understood to have two basic components; a 'coin-toss' which produces a random superposition of two states, and a displacement which moves each component of the superposition by different amounts. Here we suggest the realization of a walk in momentum space with a spinor Bose-Einstein condensate subject to a quantum ratchet realized with a pulsed, off-resonant optical lattice. By an appropriate choice of the lattice detuning, we show how the atomic momentum can be entangled with the internal spin states of the atoms. For the coin-toss, we propose to use a microwave pulse to mix these internal states. We present experimental results showing an optimized quantum ratchet, and through a series of simulations, demonstrate how our proposal gives extraordinary control of the quantum walk. This should allow for the investigation of possible biases, and classical-to-quantum dynamics in the presence of natural and engineered noise.

show abstract

Organisationen — Kommunikationssystem und Sicherheit

Cited by 13 publications

References 21 publications

Two-dimensional quantum walk under artificial magnetic field

Two-dimensional quantum walk under artificial magnetic field

Dynamically Disordered Quantum Walk as a Maximal Entanglement Generator

Quantum random walk of a Bose-Einstein condensate in momentum space

Contact Info

Product

Resources

About