Raj Mohanty

Raj Mohanty

Office: SCI, Room 206. 617-353-9297
Lab: SCI, Room B69-71. 617-353-9452



In the news:


Research Descriptions:

Applications of Nanomechanical Devices: Wireless Communications and Sensors


Our research in this specific area focuses on the development of ultra-high-frequency (UHF) oscillators, filters and frequency-selective elements for eventual use as high-speed sensors and communication systems. Our systems are nanomechanical oscillators, and they vibrate at speeds exceeding 2 GHz—the highest mechanical frequency ever reported. Because of their mechanical construct and the small size, they will enable a host of future applications. Currently, we are exploring specific applications, which include nanomechanical memory elements for high-speed high-density data storage and gigahertz-range nanomechanical oscillators for use as frequency-selecting device in cellular phones.

Development of a Semiconductor Nanochannel Sensor for Detection of Novel Melanoma Biomarker TROY


The number of cases of melanoma is rising at about 3% per year, to an estimated 62,500 new cases in 2008 in the US alone. Despite major efforts, there are still no efficacious therapies for advanced stage disease and this is not likely to change in the foreseeable future. In this regard, it would be extremely helpful to have a sensitive diagnostic blood test available that can detect early stage metastatic (occult) disease, as a small tumor load may respond better to treatment than clinically-established, metastatic disease. This blood test would also be valuable for monitoring therapy-responsiveness. Unfortunately, however, no such diagnostic blood test exists for melanoma. We will address this issue by developing a semiconductor nanochannel sensor that can detect novel melanoma biomarker TROY with sufficient sensitivity to be clinically useful. The nanoscale field-effect transistor sensor measure the conductance change of bio-functionalized nanowires, and can be configured to provide a simple, effective and potentially inexpensive method for melanoma biomarker sensing. The nanosensor technology has already been used for ultrasensitive detection of a number of proteins, including a breast cancer biomarker CA15.3 protein with a sensitivity of 2 U/mL (relevant for clinical use). The goal is to generate a semiconductor nanochannel sensor that can detect shed TROY extracellular domain at physiologically-relevant concentrations of 0.5-1 ng/mL or less. Following validation of the technology, they will obtain melanoma patient blood samples from hospitals such as BMC. We will focus on establishing TROY levels in metastatic melanoma patient samples before and after treatment to determine if TROY serum levels correlate with therapy responsiveness.

Quantum Computing: Quantum Control of Coherence of the Electron Wave Function


This project involves the development of quantum control techniques to externally control coherence properties of electron wave functions, or to increase the coherence time of electron wave functions in sub-micron and nanoscale mesoscopic systems. The main thrust behind our approach is to develop enabling technologies for increasing the coherence time scales from the usual nanosecond range to microseconds or even milliseconds. The long-term direction is to perform picosecond time-domain reflectometry and a host of quantum control techniques (open-loop, closed-loop learning feedback and bang-bang).

Quantum Nanomechanics: Quantum Motion to Testing the Limit of Quantum Mechanics


Our current research efforts in this area involve the observation of quantized displacement, energy quantization and Rabi oscillations in macroscopic mechanical oscillators. We have already observed the first two phenomena. In the next few years, we will explore approaches to use these mechanical systems as quantum bits, particularly for quantum information processing. Furthermore, we are exploring foundations of quantum mechanics with these experiments, which involve the largest quantum systems ever realized in a laboratory.

Spintronics: Control of Spins with Nanomechanical Torque


Our current research efforts in this area involve a new proposal for spintronics: spin detection and control can be done mechanical torque. We have recently proposed a comprehensive technique to carry out a series of experiments for demonstrating spin current and spin transfer across a hybrid junction of nanowire, fabricated on top of a two-element suspended torsion oscillator with sub-micron features. The proposed plan of this 3-year project is to demonstrate spin detection and control. This project involves measurement of single-spin conductance and the value of Planck’s constant.