ترغب بنشر مسار تعليمي؟ اضغط هنا

Quantum-optical state engineering up to the two-photon level

103   0   0.0 ( 0 )
 نشر من قبل Alexander I. Lvovsky
 تاريخ النشر 2009
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

We propose and experimentally verify a scheme to engineer arbitrary states of traveling light field up to the two-photon level. The desired state is remotely prepared in the signal channel of spontaneous parametric down-conversion by means of conditional measurements on the idler channel. The measurement consists of bringing the idler field into interference with two ancilla coherent states, followed by two single-photon detectors, which, in coincidence, herald the preparation event. By varying the amplitudes and phases of the ancillae, we can prepare any arbitrary superposition of zero- one- and two-photon states.



قيم البحث

اقرأ أيضاً

We propose two experimental schemes for producing coherent-state superpositions which approximate different nonclassical states conditionally in traveling optical fields. Although these setups are constructed of a small number of linear optical eleme nts and homodyne measurements, they can be used to generate various photon number superpositions in which the number of constituent states can be higher than the number of measurements in the schemes. We determine numerically the parameters to achieve maximal fidelity of the preparation for a large variety of nonclassical states, such as amplitude squeezed states, squeezed number states, binomial states and various photon number superpositions. The proposed setups can generate these states with high fidelities and with success probabilities that can be promising for practical applications.
We propose a general experimental quantum state engineering scheme for the high-fidelity conditional generation of a large variety of nonclassical states of traveling optical fields. It contains a single measurement, thereby achieving a high success probability. The generated state is encoded in the optimal choice of the physically controllable parameters of the arrangement. These parameter values are determined via numerical optimization.
The theoretical community has found interest in the ability of a two-level atom to generate a strong many-body interaction with light under pulsed excitation. Single-photon generation is the most well-known effect, where a short Gaussian laser pulse is converted into a Lorentzian single-photon wavepacket. However, recent proposals have surprisingly suggested that scattering with intense laser fields off a two-level atom may generate oscillations in two-photon emission that are out of phase with its Rabi oscillations, as the power of the pulse increases. Here, we provide an intuitive explanation for these oscillations using a quantum trajectory approach and show how they may preferentially result in emission of two-photon pulses. Experimentally, we observe signatures of these oscillations by measuring the bunching of photon pulses scattered off a two-level quantum system. Our theory and measurements provide crucial insight into the re-excitation process that plagues on-demand single-photon sources while suggesting the production of novel multi-photon states.
Continuous-variable quantum information processing through quantum optics offers a promising platform for building the next generation of scalable fault-tolerant information processors. To achieve quantum computational advantages and fault tolerance, non-Gaussian resources are essential. In this work, we propose and analyze a method to generate a variety of non-Gaussian states using coherent photon subtraction from a two-mode squeezed state followed by photon-number-resolving measurements. The proposed method offers a promising way to generate rotation-symmetric states conventionally used for quantum error correction with binomial codes and truncated Schr{o}dinger cat codes. We consider the deleterious effects of experimental imperfections such as detection inefficiencies and losses in the state engineering protocol. Our method can be readily implemented with current quantum photonic technologies.
142 - N. Timoney , I. Usmani , P. Jobez 2013
A long-lived quantum memory is a firm requirement for implementing a quantum repeater scheme. Recent progress in solid-state rare-earth-ion-doped systems justifies their status as very strong candidates for such systems. Nonetheless an optical memory based on spin-wave storage at the single-photon-level has not been shown in such a system to date, which is crucial for achieving the long storage times required for quantum repeaters. In this letter we show that it is possible to execute a complete atomic frequency comb (AFC) scheme, including spin-wave storage, with weak coherent pulses of $bar{n} = 2.5 pm 0.6$ photons per pulse. We discuss in detail the experimental steps required to obtain this result and demonstrate the coherence of a stored time-bin pulse. We show a noise level of $(7.1 pm 2.3)10^{-3}$ photons per mode during storage, this relatively low-noise level paves the way for future quantum optics experiments using spin-waves in rare-earth-doped crystals.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا