Main Page | Quantum Physics

Research

At present, I am working on the most intriguing research problems of quantum physics. In particular my current research focus is on quantum to classical transition. In this context, I am setting up new and original experiments to understand the notion of reality more deeply. In my lab at IISER Mohali, experiments are being carried out with quantum entangled photons and Bose Einstein condensate. I also do research on the main principles of quantum physics and their physical implication.

This webpage is a short introduction about my research and research from my lab.

Photon Experiments

Photon Entanglement and Quantum Diffraction

Quantum entangled state cannot be written in a product form even if individual particles are separated. Research on quantum entangled photons and foundations of quantum mechanics is one of the main research interests.

In my lab at IISER Mohali, we have performed a new experiment to produce position-momentum entangled states of two photons. Quantum diffraction of position-momentum entangled photons from a sharp edge is experimentally observed. Experimental results are understood based on a continuous variable entanglement quantum model. This is the first experiment on quantum diffraction of entangled photons from a sharp edge that involves continuous variable entanglement. For details: Phys. Letts. A. 383, 125889, (2019).

Quantum diffraction from a sharp edge

Experimental diffraction pattern of position-momentum entangled photons (dotted). Solid line plot represents a plot generated by continuous variable entanglement model.

Selected Research

Macroscopic quantum entanglement

This section is about my research on quantum magnetic fields and their interaction with atoms.

Fields are quantum of nature and particles are energy excitation of a field. Quantum superposition of magnetic field can produce interesting quantum states of interacting BEC. One such quantum state is a macroscopic entanglement of path of a single Bose Einstein condensate. Quantum magnetic field can produce macroscopic quantum entanglement of BEC.

Further details: Mandip Singh, Phys. Rev. A. 95, 043620, (2017)

Macroscopic quantum system

This research work is about generalization of a flux qubit.

Displacement of a close loop superconducting cantilever is coupled with the net magnetic flux linked to the loop. Its ground state has features of quantum entanglement. Coupling constant of cantilever displacement with the net magnetic flux depends on the external magnetic field. In this way, coupling can be controlled externally and quantum entanglement of macroscopic quantum variables can be produced. Mandip Singh, Phys. Letts A. 370, 2001-2006 (2015).

Phase space Imaging Experiment

3D Tomographic imaging of a phase space pattern

I have introduced the conceptual idea of localization and imaging of patterns in a phase space. I performed experiment on this concept in 2017 and published it in 2018.

Patterns in phase space cannot be imaged with a lens and eye. This research is about imaging of a pattern localised in a phase space. A part of the experiment on a three-dimensional tomographic imaging of a phase space pattern is shown on left.

For details: Phys. Rev. A, 98, 053828 (2018).

Concept

Concept of a 3D tomographic imaging of a pattern in phase space (a).

(d) velocity selective hole-burning and

Phase Space Tomographic Imaging

Schematic diagram of experiment. For details: Phys. Rev. A, 98, 053828 (2018).

phy-edu

This section highlights published work in physics education research.

Experiment of diffraction of laser beam from moving sharp edges is featured on the cover page of American Journal of Physics, June 2018.

Diffraction effects in mechanically chopped laser pulses. S. Gambhir and M. Singh, 86, 406, (2018).

Nonlinearity of PN junction diode.

This experiment shows all orders of nonlinearity of a PN junction diode. Harmonic generation, sum difference frequency generation, frequency comb generation up to the twentieth harmonic by a single PN junction. (IAPT Physics Education,Vol 32, 2, Apr-Jun 2018, ISSN: 0970-5953.)

Frequency comb generation up to twentieth harmonic of the fundamental driving voltage.

Frequency comb generation by a PN junction diode

A frequency comb generated by using nonlinearity of a PN junction diode. Highest frequency is the twentieth harmonic of the driving voltage. Published in IAPT physics education, Apr-Jun 2018.

Dr. Mandip Singh