Monthly Archives: February 2013

QIP 2013 from the perspective of a greenhorn (grad student)

Posted on by
3
caltechCrew_qip2013

Most of Caltech’s contingent during QIP’s banquet. Not pictured: sword dancers, jug balancers and Gorjan.

A couple of weeks ago, about half of IQI (now part of IQIM) flew from Pasadena to Beijing in order to attend QIP 2013, the 16th annual workshop on quantum information processing. I wish I could report that the quantum information community solved the world’s problems over the past year, or at least built a 2^10 qubit universal quantum computer, but unfortunately, we’re not quite there yet. As a substitute, I’ll mention a few of the talks that I particularly enjoyed and the really hard open problems that they left us with.

The emphases of the talks mainly bifurcated towards computer science versus physics. I was better prepared to understand the talks emphasizing the latter, so my comments will mainly describe those talks. Patrick Hayden’s talk: “summoning information in spacetime: or where and when can a qubit be?” was one of my favorites. To the extent that I understood things, the goal of this work is to better understand how quantum information can propagate forward in time. If a qubit were created at spacetime location S, and then if it were forced to remain localized, the no-cloning theorem would give strict bounds regarding how it could move forward in time. The qubit would follow a worldline and that would be the end of things. However, qubits don’t need to remain localized, as teleportation experiments have pretty clearly demonstrated, and it therefore seems like qubits can propagate into the future in more subtle ways–ways that at face value appear to violate the no-cloning theorem. Patrick and the undergraduate that he worked with on this project, Alex May, came up with a pictorial approach to better understand these subtleties. The really hard open problems that these ideas could potentially be applied to include: firewalls, position-dependent quantum cryptography and to paradoxes concerning the apparent no-cloning violations near black hole event horizons.
Continue reading →

Grad student life: high highs and low lows

Posted on by
1
Conference for Undergraduate Women in Physics, Caltech, 19 January 2013

Conference for Undergraduate Women in Physics, Caltech, 19 January 2013.

On January 18-20, Caltech was one of the host campuses for the annual Conference for Undergraduate Women in Physics. Nearly 200 women attended here, mostly physics majors from the western US. It was an exciting and fun event, packed with talks, panel discussions, lab tours, a poster session, and other activities.

One highlight was a screening of The PhD Movie, followed by a discussion with director Jorge Cham and the cast (real-life Caltech grad students Alex Lockwood and Crystal Dilworth, and undergrad Raj Katti). The movie, filmed on location at Caltech, provides a very funny look at the misery of graduate student life. You can get a pretty accurate impression of the movie’s tone by viewing the trailer. The discussion afterward featured poignant warnings about the pitfalls of graduate school, and emphasized the importance of having the right mentor.

I found myself reflecting on my own experience. Graduate school will sometimes deal grave blows to your self confidence, but it can also be a time of exhilarating intellectual growth. The highs are high but the lows are low.

One thing we try to do at Quantum Frontiers is provide a variety of perspectives on the graduate student experience by featuring our students as contributors. Today we’ll try something a bit different: a profile of grad student Debaleena Nandi from Caltech writer Ann Wendland.

Of Bravery, Support, and Breakthroughs
By Ann Wendland

Debaleena Nandi, in the lab as usual.

Debaleena Nandi, in the lab as usual.

In March 2008, a graduate student at the Indian Institute of Science (IISc) named Debaleena Nandi heard Caltech physics professor Jim Eisenstein give a series of lectures on two-dimensional systems of quantum electronic matter. “I was very keen to take a peek into his lab,” she says—so keen that, with a friend by her side for moral support, she walked up to Eisenstein and asked if she could join his group for the summer. Eisenstein had noted her smart questions during his talks and said he was open to the idea. Still, he was surprised when he returned to Caltech and found she’d e-mailed him. A few months later, Nandi rented an apartment in Pasadena and left India for the first time.

Continue reading →