4 and discussion. MB is supported by the Swiss NSF and MaNEP. times smaller than they expected. These data at N ≫ 1 indeed correspond to our predictions that 〈 R$_{4t}$ 〉 = 0 and its fluctuations are strongly diminished by an increased voltage probe coupling. Their numerical data are well- fitted by Eq. (3), which demonstrates a weak dependence on N$_{3}$ − N$_{4}$ and does not depend on β = 1 , 2. Reasons for the much reduced experimental 〈 R 2 4t 〉 are strong deco- herence, which might depend on couplings, and possibly direct source-drain trajectories, which result in voltage drop fluctuations smaller than expected by RMT. High-frequency experiments are more difficult. If a leakage current through C bypasses the drain, we have I$_{1}$$_{ω}$ = − I$_{2}$$_{ω}$ . Resistance R$_{4t}$ relates the voltage drop V$_{34}$ to some linear combination of these currents, and our R$_{4t}$ corresponds to ( I$_{1}$$_{ω}$ − I$_{2}$$_{ω}$ ) / 2. If the voltage drop is mea- sured via a transmission line with length comparable to 2 πc/ω , the circuit should be also taken into account. The phase shift of transmitted voltage with respect to current source has a classical component due to the circuit and a fluctuating part φ due the dot, and we consider its meso- scopic distribution P ( φ ). If the line impedance between the exits 3,4 (1,2) is large compared to R$_{4t}$ ( R$_{2t}$ ), one has φ = arg R$_{4t}$ . Using Eqs. (3,5) and 〈| R$_{4t}$ | $^{2}$〉 calculated similarly, and normalizing ∮ dφP ( φ ) = 2 π , we find This π -periodic distribution is insensitive to the probe properties and dephasing. The position φ$_{0}$ and the height of the distribution maximum are defined by Eq. (8), and Fig. 1(b) presents P ( φ ) for low T ≪ ℏ /τ$_{d}$ . The maxi- mum √$_{2}$$_{/ωτ}$$_{d}$ at φ$_{0}$ = ωτ$_{d}$ for ωτ$_{d}$ 1 is sharp and the reactive part of R$_{4t}$ is small. At ωτ$_{d}$ ≫ 1 the peak at φ$_{0}$ = π/ 2 − log$_{2}$ ωτ$_{d}$/ (4 ωτ$_{d}$ ) is small due to weak corre- lations between (re)active parts, and any phase φ is pos- sible. For high T ≫ ℏ ω, ℏ /τ$_{d}$ when RMT is still valid, one has P ( φ ) = ωτ$_{d}$/ [ √ 1 + ω $^{2}$τ 2 d − cos(2 φ − arctan ωτ$_{d}$ )], qualitatively similar to the low- T result. We expect that the universal distribution given by Eq. (8) can be found from phase measurements by varying either ω or T . Conclusions. We discuss statistics of multi-terminal transport through a well-conducting chaotic quantum dot with imperfect coupling. Using RMT we find that four- probe resistance is unaffected by weak localization and its fluctuations are governed only by the dwell-time. Unlike two-probe transport, the four-terminal one is insensitive to the Coulomb interactions at any frequency, suggesting that the charge-relaxation time is connected to the mea- surement scheme. The fluctuations are given by a single analytical expression for arbitrary temperature, ac fre- quency, non-ideal coupling of the contacts, and floating probes. We propose a universal mesoscopic distribution for the phase of voltage transmitted through the dot. Acknowledgments. We would like to thank K. Flens- berg, J. Gabelli, and C. M. Marcus for useful comments [34] J. B. Pieper and J. C. Price, Phys. Rev. B 49 , 17059 (1994). [1] Y. Imry, Introduction to Mesoscopic Physics (Oxford University Press, USA, 2002). [2] B. L. Altshuler, P. Lee, and R. Webb, eds., Meso- scopic Phenomena in Solids (North-Holland, Amster- dam, 1991). [3] L. J. van der Pauw, Philips Reserarch Reports 13 , 1 (1958). [4] M. B¨ uttiker, Phys. Rev. Lett. 57 , 1761 (1986). [5] M.B¨ uttiker, IBM Journal Research Development 32 , 317 (1988). [6] R. De Picciotto et al. , Nature 411 , 51 (2001). [7] B. Gao et al. , Phys. Rev. Lett. 95 , 196802 (2005). [8] G. Gunnarsson, J. Trbovic, and C. Schonenberger, Phys- ical Review B 77 , 201405 (2008). [9] A. D. Benoit et al. , Phys. Rev. Lett. 57 , 1765 (1986). [10] M. Ma and P. A. Lee, Phys. Rev. B 35 , 1448 (1987). [11] B. Z. Spivak and A. Yu. Zyuzin, in [2]. [12] H. U. Baranger, A. D. Stone, and D. P. DiVincenzo, Phys. Rev. B 37 , 6521 (1988). [13] C. L. Kane, P. A. Lee, and D. P. DiVincenzo, Phys. Rev. B 38 , 2995 (1988). [14] S. Iida and A. M¨ uller-Groeling, Phys. Rev. B 44 , 8097 (1991). [15] B. Schmidt and A. M¨ uller-Groeling, Phys. Rev. B 47 , 12732 (1993). [16] C. W. J. Beenakker, Rev. Mod. Phys. 69 , 731 (1997). [17] I. L. Aleiner, P. W. Brouwer, and L. I. Glazman, Physics Reports 358 , 309 (2002). [18] A. I. Lerescu, E. J. Koop, C. H. van der Wal, B. J. van Wees, and J. H. Bardarson, arXiv:0705.3179 (2007). [19] P. W. Brouwer and C. W. J. Beenakker, Physical Review B 55 , 4695 (1997). [20] P. W. Brouwer and C. W. J. Beenakker, Journal of Math- ematical Physics 37 , 4904 (1996). [21] P. Brouwer and M. B¨ uttiker, Europhysics Letters 37 , 441 (1997). [22] M. L. Polianski, P. Samuelsson, and M. B¨ uttiker, Physi- cal Review B 72 , 161302 (2005). [23] K. E. Nagaev, S. Pilgram, and M. B¨ uttiker, Phys. Rev. Lett. 92 , 176804 (2004). [24] C. Petitjean et al. , Phys. Rev. B 80 , 115310 (2009). [25] M. B¨ uttiker, A. Prˆ etre, and H. Thomas, Phys. Rev. Lett. 70 , 4114 (1993). [26] P. W. Brouwer, Phys. Rev. B 51 , 16878 (1995). [27] M. L. Polianski and P. W. Brouwer, Journal of Physics A: Mathematical and General 36 , 3215 (2003). [28] M. L. Polianski, Physical Review B 80 , 241301 (2009). [29] P. W. Brouwer, A. Lamacraft, and K. Flensberg, Physical Review B 72 , 075316 (2005). [30] T. Ihn et al. , Physica E 40 , 1851 (2008). [31] Y. M. Blanter and M. B¨ uttiker, Physics Reports 336 , 1 (2000). [32] K. M. Schep and G. E. W. Bauer, Phys. Rev. Lett. 78 , 3015 (1997). [33] M. B¨ uttiker, Phys. Rev. B 33 , 3020 (1986).