Irfan Siddiqi

Research Expertise and Interest

condensed matter physics, superconducting qubits, quantum limited amplifiers, quantum circuits

Research Description

Irfan Siddiqi is a professor in the Department of Physics.  Quantum mechanics is a theory that was developed to explain the properties of atoms and light. It is one of the most thoroughly tested and successful theories in the history of science. It is also one of the most controversial ones. For over 80 years, quantum mechanics has stirred up deep debate amongst physicists, in particular about the notion that an object can be in a coherent superposition of two states simultaneously. Moreover, since the mass of an object does not directly enter into the quantum formalism, the theory should be applicable to all objects in the universe, thus raising deep philosophical questions about how then one obtains classical behavior if the word is actually quantum.

The Quantum Nanoelectronics Laboratory investigates the quantum coherence of various condensed matter systems ranging from microscopic nanomagnets such as single molecule magnets to complex macroscopic electrical circuits. To measure the electric and magnetic properties of these quantum systems, they are developing novel microwave frequency quantum-noise-limited amplifiers based on superconducting Josephson junctions formed by both oxide tunnel barriers and carbon nanotube weak links. Current topics of research include the dependence of quantum coherence on system complexity, the non-equilibrium quantum statistical mechanics of non-linear oscillators, the quantum coherence of single molecules, and topological architectures for maximum coherence in superconducting circuits.

In the News

From Bits to Qubits

Irfan Siddiqi and Heather Gray weigh in about the fundamentals of quantum computing in this article published in Symmetry.

Going Beyond Qubits

A team led by physicists at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley has successfully observed the scrambling of quantum information, which is thought to underlie the behavior of black holes, using qutrits: information-storing quantum units that can represent three separate states at the same time. Their efforts also pave the way for building a quantum information processor based upon qutrits.

The Quantum Information Edge Launches

A nationwide alliance of national labs, universities, and industry launched today to advance the frontiers of quantum computing systems designed to solve urgent scientific challenges and maintain U.S. leadership in next-generation information technology.

Can entangled qubits be used to probe black holes?

Physicists have used a seven-qubit quantum computer to simulate the scrambling of information inside a black hole, heralding a future in which entangled quantum bits might be used to probe the mysterious interiors of these bizarre objects.

Berkeley Lab to Build Advanced Quantum Computing Testbed

The U.S. Department of Energy announced today that Lawrence Berkeley National Laboratory (Berkeley Lab) will receive $30 million over five years to build and operate an Advanced Quantum Testbed (AQT). Researchers will use the testbed to explore superconducting quantum processors and evaluate how these emerging quantum devices can be utilized to advance scientific research.