arXiv subjects

Guo-Ping Guo

Publications and source records attributed to Guo-Ping Guo.

At least 199 records · Page 11Linked to original sources

arXiv2008

Interference of surface plasmon polaritions controlled by the phase of incident light

Interference patterns of surface plasmon polaritons(SPPs) are observed in the extraordinary optical transmission through subwavelength holes in optically thick metal plate. It is found that the phase of incident light can be transferred to SPPs. We can control the destructive and constructive interference of SPPs by modulating the relative phase between two incident beams. Using a slightly displaced Mach-Zehnder interferometer, we also observe a SPPs interference pattern composed of bright and dark stripes.

physics.optics↗

arXiv2008

Dispersive Coupling Between the Superconducting Transmission Line Resonator and the Double Quantum Dots

Realization of controllable interaction between distant qubits is one of the major problems in scalable solid state quantum computing. We study a superconducting transmission line resonator (TLR) as a tunable dispersive coupler for the double-dot molecules. A general interaction Hamiltonian of $n$ two-electron spin-based qubits and the TLR is presented, where the double-dot qubits are biased at the large detuning region and the TLR is always empty and virtually excited. Our analysis o the main decoherence sources indicates that various major quantum operations can be reliably implemented with current technology.

quant-ph↗

arXiv2008

Eliminating interactions between non-neighboring qubits in the preparation of cluster states in quantum molecules

We propose a scheme to eliminate the effect of non-nearest-neighbor qubits in preparing cluster state with double-dot molecules. As the interaction Hamiltonians between qubits are Ising-model and mutually commute, we can get positive and negative effective interactions between qubits to cancel the effect of non-nearest-neighbor qubits by properly changing the electron charge states of each quantum dot molecule. The total time for the present multi-step cluster state preparation scheme is only doubled for one-dimensional qubit chain and tripled for two-dimensional qubit array comparing with the time of previous protocol leaving out the non-nearest-neighbor interactions.

quant-ph↗

arXiv2007

Quantum Computation and Bell-state Measurement with Double-Dot Molecules

We propose a quantum computation architecture of double-dot molecules, where the qubit is encoded in the molecule two-electron spin states. By arranging the two dots inside each molecule perpendicular to the qubit scaling line, the interactions between neighboring qubits are largely simplified and the scaling to multi-qubit system becomes straightforward. As an Ising-model effective interaction can be expediently switched on and off between any two neighboring molecules by adjusting the potential offset between the two dots, universal two-qubit gates can be implemented without requiring time-dependent control of the tunnel coupling between the dots. A Bell-state measurement scheme for qubit encoded in double-dot singlet and triplet states is also proposed for quantum molecules arranged in this way.

quant-ph↗

arXiv2007

Influence of unsymmetrical periodicity on extraordinary transmission through periodic arrays of subwavelength holes

Quadrate hole array is explored to study the influence of unsymmetrical periodicity on extraordinary optical transmission through periodic arrays of subwavelength holes. It is found that the transmission efficiency of light and the ratio between transmission efficiencies of horizontal and vertical polarized light can be continuously tuned by rotating the quadrate hole array. We can calculate out the transmission spectra (including the heights and locations of peaks) for any rotation angle $θ$ with a simple theoretical model.

physics.optics↗

arXiv2007

One-step preparation of cluster states in quantum dot molecules

Cluster states, a special type of highly entangled states, are a universal resource for measurement-based quantum computation. Here, we propose an efficient one-step generation scheme for cluster states in semiconductor quantum dot molecules, where qubits are encoded on singlet and triplet state of two coupled quantum dots. By applying a collective electrical field or simultaneously adjusting interdot bias voltages of all double-dot molecule, we get a switchable Ising-like interaction between any two adjacent quantum molecule qubits. The initialization, the single qubit measurement, and the experimental parameters are discussed, which shows the large cluster state preparation and one-way quantum computation implementable in semiconductor quantum dots with the present techniques.

quant-ph↗

arXiv2007

Scaling Behavior and Variable Hopping Conductivity in the Quantum Hall Plateau Transition

We have measured the temperature dependence of the longitudinal resistivity $% ρ_{xx}$ of a two-dimensional electron system in the regime of the quantum Hall plateau transition. We extracted the quantitative form of scaling function for $ρ_{xx}$ and compared it with the results of ordinary scaling theory and variable range hopping based theory. We find that the two alternative theoretically proposed scaling functions are valid in different regions.

cond-mat.mes-hall↗

arXiv2006

Plasmon assisted transmission of high dimensional orbital angular momentum entangled state

We present an experimental evidence that high dimensional orbital angular momentum entanglement of a pair of photons can be survived after a photon-plasmon-photon conversion. The information of spatial modes can be coherently transmitted by surface plasmons. This experiment primarily studies the high dimensional entangled systems based on surface plasmon with subwavelength structures. It maybe useful in the investigation of spatial mode properties of surface plasmon assisted transmission through subwavelength hole arrays.

quant-ph↗

arXiv2006

Quantum Non-Demolition Bell State Measurement and N-party GHZ State Preparation in Quantum Dot

By exploiting the fermionic qubit parity measurement, we present a scheme to realize quantum non-demolition (QND) measurement of Bell-states and generate n-party GHZ state in quantum dot. Compared with the original protocol, the required electron transfer before and after parity measurement can be nonadiabatic, which may speed up the operation speed and make the omitting of spin-orbit interaction more reasonable. This may help us to construct CNOT gate without highly precise control of coupling as the way of D. Gottesman and I. L. Chuang.

quant-ph↗

arXiv2006

Spatial mode properties of plasmon assisted transmission

Orbital angular momentum of photons is explored to study the spatial mode properties of plasmon assisted transmission process. We found that photons carrying different orbital angular momentums have different transmission efficiencies, while the coherence between these spatial modes can be preserved.

quant-ph↗

arXiv2006

Observation of the Preservation of the Two-Photon Coherence in Plasmon-assisted Transmission

We experimentally study two-photon coherence in plasmon-assisted transmission with a two-photon Mach-Zehnder (MZ) interferometer. Two collinear photons of identical or orthogonal polarization are simultaneously incident on one optically thick metal film, perforated with a periodic array of subwavelength holes. The de Broglie wavelength of plasmon-assisted transmitted photons is measured, which shows that two photons are re-eradiated by the plasmons and the quantum coherence of biphoton is preserved in the conversion process of transforming biphoton to plasmons and then back to biphoton.

quant-ph↗

arXiv2005

Entanglement of the Hermite-Gaussian modes states of photons

We found that the Hermit-Gaussian(HG) modes of the down converted beams from the spontaneous parametric down conversion are quasi-conserved and the generated photon pairs are HG modes entangled for some special cases. This is valuable for either the investigation of fundament properties of multi-dimensional entanglement or quantum information applications.

quant-ph↗

arXiv2005

Engineering of multi-dimensional entangled states of photon pairs using hyper-entanglement

Multi-dimensional entangled states have been proven to be more powerful in some quantum information process. In this paper, down-converted photons from spontaneous parametric down conversion(SPDC) are used to engineer multi-dimensional entangled states. A kind of multi-degree multi-dimensional Greenberger-Horne-Zeilinger(GHZ) state can also be generated. The hyper-entangled photons, which are entangled in energy-time, polarization and orbital angular momentum (OAM), is proved to be useful to increase the dimension of systems and investigate higher-dimensional entangled states.

quant-ph↗

arXiv2003

Preparation of multi-party entanglement of individual photons and atomic ensembles

An experimental feasible scheme is proposed to generate Greenberger-Horne-Zeilinger (GHZ) type of maximal entanglement. Distinguishing from the previous schemes, this entanglement can be chosen between either atomic ensembles (stationary qubit) or individual photons (flying qubit), according to the difference applications we desire for it. The physical requirements of the scheme are moderate and well fit the present experimental techinque.

quant-ph↗

arXiv2003

Entanglement of individual photon and atomic ensembles

Here we present an experimentally feasible scheme to entangle flying qubit (individual photon with polarization modes) and stationary qubit (atomic ensembles with long-lived collective excitations). This entanglement integrate two different species can act as a critical element for the coherent transform of quantum information between flying and stationary qubits. The entanglement degree can be also adjusted expediently with linear optics. Furthermore, the present scheme can be modified to generate this entanglement in a way event-ready with the employment of a pair of entangled photons. Then successful preparation can be unambiguously heralded by coincident between two single-photon detectors. Its application for individal photons quantum memory is also analyzed. The physical requirements of all those preparation and applications processing are moderate, and well fit the present technique.

quant-ph↗

arXiv2003

Orbital angular momentum of the down converted photons

We calculate the relative amplitude of orbital angular momentum (OAM) entangled photon pairs from the spontaneous parametric down conversion. The results show that the amplitude depends on both the two Laguerre indices l, p. We also discuss the influences of the mostly used holograms and mono-mode fibers for mode analyzation. We conclude that only a few dimensions can be explored from the infinite OAM modes of the down-converted photon pairs.

quant-ph↗

arXiv2003

Quantum data hiding with spontaneous parameter down-conversion

Here we analyze the practical implication of the existing quantum data hiding protocol with Bell states produced with optical downconverter. We show that the uncertainty for the producing of the Bell states with spontaneous parameter down-conversion should be taken into account, because it will cause serious trouble to the hider encoding procedure. A set of extended Bell states and a generalized Bell states analyzer are proposed to describe and analyze the possible states of two photons distributing in two paths. Then we present a method to integrate the above uncertainty of Bell states preparation into the dating hiding procedure, when we encode the secret with the set of extended Bell states. These modifications greatly simplify the hider's encoding operations, and thus paves the way for the implementation of quantum data hiding with present-day quantum optics.

quant-ph↗

arXiv2002

Quantum secret sharing without entanglement

After analysing the main quantum secret sharing protocol based on the entanglement states, we propose an idea to directly encode the qubit of quantum key distributions, and then present a quantum secret sharing scheme where only product states are employed. As entanglement, especially the inaccessable multi-entangled state, is not necessary in the present quantum secret sharing protocol, it may be more applicable when the number of the parties of secret sharing is large. Its theoretic efficiency is also doubled to approach 100%.

quant-ph↗