Exploring Macroscopic Entanglement with a Single Photon and Coherent States

Entanglement between macroscopically populated states can easily be created by combining a single photon and a bright coherent state on a beam-splitter. Motivated by the simplicity of this technique, we report on a method using displacement operations in the phase space and basic photon detections to reveal such an entanglement. We demonstrate through preliminary experimental results, that this eminently feasible approach provides an attractive way for exploring entanglement at various scales, ranging from one to a thousand photons. This offers an instructive viewpoint to gain insight into the reasons that make it hard to observe quantum features in our macroscopic world.Comment: 6 pages, 10 figures. v2: Updated version. The corresponding experiment is reported in arXiv:1212.3710. See also arXiv:1306.084

Manipulating time-bin qubits with fiber optics components

We propose two experimental schemes to implement arbitrary unitary single qubit operations on single photons encoded in time-bin qubits. Both schemes require fiber optics components that are available with current technology.Comment: 2 pages, 3 figures, to be published in the proceedings of the IEEE LEOS 2006 topical meeting, Quebec city, Canada, July 200

United States of Banana: A Postcolonial Dramatic Fiction

This paper wants to be a recollection of the process of staging the play “United States of Banana”, based on the original text written by Puerto Rican author Giannina Braschi. This work has been widely praised by academics both in and outside the United States and has opened new spaces to reflect on the ideas that concern the Latino population living in the US. These literary expressions are the sign of a vital community that is slowly assuming a historical role in the shaping of the most powerful nation in the planet. Since I consider theater to be a social thermometer, I chose this play as my thesis project to testify about the state of affairs regarding the situation of Puerto Rico. Its lack of sovereignty and self-regulation constitute a metaphor about the foreign policy the government of the United States has exercised in many countries, but especially in Latin America. However, it is also time to set our own proposals over the table and abandon the paternalist model that justifies and supports our attitude of beneficiaries of the charities coming from the first world. In this play, characters from Classical literature become symbols of entire races and populations to polish a gigantic mirror in which we can look at ourselves. Despite its scathing humor and harrowing critique, the text helped us create a performative event in 6 which we all, creators and spectators, shared a common responsibility: that of contributing to making a world that is fairer and a society that finds hope more easily

Developing Meaningful Carbon Offsets for Bates College

This project was conducted, as a template, to make Bates College a more sustainable energy community. By recommending renewable energy certificates (RECs) and carbon offsets that are meaningful to the Bates Committee on Environmental Responsibility we have provided a roadmap for the college to obtain its ultimate goal of carbon neutrality. The aim of this project was to provide a general overview of the REC and carbon offset market for our community project partner Julie Rosenbach, the Manager of Sustainability Initiatives at Bates College. We are offering five recommendations of RECs and carbon offsets that are meaningful investments for Bates College and its community. RECs are defined as carbon offset that “represent the environmental and other non-power attributes of renewable electricity generation and are a component of all renewable electricity products” (EPA 2014). A single Class I REC represents 1000 kilowatt-hours of electricity that is generated from a renewable energy source (e.g. wind, hydroelectric, solar, or biomass) (EPA 2014). Purchased RECs represent that the owner is using electric power generated from a carbon-free source. RECs have been available for decades, but recently have gained more traction as a practical way to obtaining carbon neutrality as clearer definitions and measures have been put in place (Main 2007). Similarly, carbon offsets, “a unit of carbon dioxide-equivalent (CO2e) that is reduced, avoided, or sequestered to compensate for emissions occurring elsewhere,” provide an alternative way to reduce a carbon footprint (Goodward & Kelly, 2010). Bates College, after signing the American College and University Presidents’ Climate Commitment or ACUPCC, has elected to pursue climate neutrality thus entering the voluntary carbon offset market. Our five recommendations are based on our findings within the market and how we defined an offset program as meaningful. Developing a definition and criteria for meaningful RECs and carbon offsets was crucial in the process of selecting our recommended programs for Bates College to invest in. We considered many factors surrounding the idea of a sustainable community and how to create a positive impact on the environment of and around Bates College through investing in locally meaningful offset programs. Our definition of meaningful entails four major categories: Locality, Additionality, Cost-effectiveness, and an Educational component. Locality refers to the permanence, closed-looped nature, and potential economic benefits of an offset. These three sub-categories are all necessary for a program to have an aspect of “additionality”. Additionality is a unique part of the definition of a carbon offset, and references the idea that further invested monies from the consumer, beyond the price of electric power, is necessary for the continuation of the program either through maintenance costs, continued growth of infrastructure, or further innovation. Cost effectiveness is the theoretical and future net gain of investing in an offset program. Finally, we want our recommendation to have an education component or have educational potential for the Bates College community. Our final recommendations were determined through the use of our defined criteria of a meaningful carbon offset program. The programs contained in this report will provide Bates College with a variety of options on how to achieve climate neutrality in a meaningful and sustainable way

Saturation of the Raman amplification by self-phase modulation in silicon nanowaveguides

We experimentally show that the self-phase modulation of picosecond pump pulses, induced by both the optical Kerr effect and free-carrier refraction, has a detrimental effect on the maximum on-off Raman gain achievable in silicon on insulator nanowaveguides, causing it to saturate. A simple calculation of the Raman gain coefficient from the measured broadened output pump spectra perfectly matches the saturated behavior of the amplified Raman signal observed experimentally at different input pump powers.Comment: Accepted for publications in Applied Physics Letter

Transanal endoscopic microsurgical excision of rectal tumors: Indications and results

Transanal endoscopic microsurgery (TEM) allows local excision of rectal tumors located 4 to 18 cm above the anal verge. The technique is not yet generally established because of the necessary special instrumentation and tools, the unusual technical aspects of the approach, and the stringent patient selection criteria. The aim of this prospective, descriptive study was to analyze the currently accepted indications for TEM and to evaluate the use of this procedure for treating rectal cancer. Over a 4-year period 50 patients aged 31 to 86 years (mean 64 years) underwent TEM for treatment of rectal tumors located 12 cm above the anal verge (range 4-18 cm). The local complication rate was 4%. Altogether, 76% of lesions were benign, and 24% were T1 and T2 tumors. Of 12 cancer cases, 4 required reoperation by total mesorectal resection; the other 8 are currently under follow-up management. Over the follow-up period of 30.6 months (range 11-54 months) the recurrence rate of T1 tumors was 8.3%. TEM is a minimally invasive surgical technique that may benefit a small, specific population of patients with rectal tumors. Compared with conventional transanal resection, TEM provides superior exposure of tumors higher up in the rectum (i.e., up to 18 cm from the anal verge). The greater precision of resection combined with low morbidity (10%, relative to that of anterior resection) and short duration of hospitalization (5.5 days) make this technique a reliable and in some cases more effective surgical approach than laparotomy and low anterior resectio

A source of polarization-entangled photon pairs interfacing quantum memories with telecom photons

We present a source of polarization-entangled photon pairs suitable for the implementation of long-distance quantum communication protocols using quantum memories. Photon pairs with wavelengths 883 nm and 1338 nm are produced by coherently pumping two periodically poled nonlinear waveguides embedded in the arms of a polarization interferometer. Subsequent spectral filtering reduces the bandwidth of the photons to 240 MHz. The bandwidth is well-matched to a quantum memory based on an Nd:YSO crystal, to which, in addition, the center frequency of the 883 nm photons is actively stabilized. A theoretical model that includes the effect of the filtering is presented and accurately fits the measured correlation functions of the generated photons. The model can also be used as a way to properly assess the properties of the source. The quality of the entanglement is revealed by a visibility of V = 96.1(9)% in a Bell-type experiment and through the violation of a Bell inequality.Comment: 15 pages, 8 figures, 3 table