Hrant Gharibyan

Welcome to my website :)

I am an "It from Qubit" postdoctoral scholar at California Institute of Technology (Caltech), working in Prof. John Preskill's group at the Institute of Quantum Information and Matter.

I completed my Ph.D in physics at Stanford University in 2019 under supervision of Prof. Leonard Susskind. I have earned my Master's degree in physics at Stanford in 2017 and Bachelor's degreed in physics and mathematics at MIT in 2014. My current research interests are in the interface of quantum information science and quantum gravity. My recent work has contributed to growing body of work illustrating that properties of quantum computation/information play an important role in understanding fundamental puzzles about black holes, wormholes, and new phases of matter.

If you have any question or comments, please feel free to contact me at hrant(at)

Recent Projects

Quantum Gravity in the Lab

Teleportation by Size and Traversable Wormholes,

Part I and Part II

​One of my recent research articles used the model of traversable wormholes in holography to develop a new kind of teleportation protocol. We have dubbed this protocol, teleportation by size, and written the paper Quantum Gravity in the Lab. Experimental realizations of this protocol on a superconducting quantum computer and ion trap quantum devices can probe many interesting features of Einstein’s gravity, such as existence of wormholes and the scrambling of information in black holes.

Simulating Superstring/M-theory on a Quantum Computer

We present a novel framework for simulating matrix models on a quantum computer. Supersymmetric matrix models have natural applications to superstring/M-theory and gravitational physics, in an appropriate limit of parameters. Furthermore, for certain states in the Berenstein-Maldacena-Nastase (BMN) matrix model, several supersymmetric quantum field theories dual to superstring/M-theory can be realized on a quantum device.

Complexity and Geometry

The Python's Lunch: geometric obstructions to decoding Hawking radiation

​Approaching a question from the angle of geometry, I recently wrote a paper entitled Python’s Lunch that conjectured a direct connection between the quantum complexity of decoding the information that fell into a black hole and a geometric bulge in the wormhole geometry. The wormhole that connects the Hawking radiation to the remaining black hole has a large bulge in the middle, hence the name python’s lunch. This finding is yet more evidence for the strong link between quantum computation and laws of gravity.

Quantum Chaos and Random Circuits

Onset of Random Matrix Behavior in Scrambling Systems

The fine grained energy spectrum of quantum chaotic systems is widely believed to be described by random matrix statistics. A basic scale in such a system is the energy range over which this behavior persists. We define the corresponding time scale by the time at which the linearly growing ramp region in the spectral form factor begins. We call this time tramp. The purpose of this paper is to study this scale in many-body quantum systems that display strong chaos, sometimes called scrambling systems. We focus on randomly coupled qubit systems, both local and k-local (all-to-all interactions) and the Sachdev--Ye--Kitaev (SYK) model. Using numerical results for Hamiltonian systems and analytic estimates for random quantum circuits we find the following results.